|•Bakubottom oneshot's•|

°Follow You° Dekubaku

Summeray : “I’ll follow him,” Deku says. “I’ll follow the trail of Kacchan until I die.”

ao3 author : All credits to | Mermaidmayonnaise |

Every Thursday at 3 PM when the bell signals the end of the school day, Katsuki goes to chess club.

He’s smart, and he knows this because he’s been told so his entire life. Being intelligent isn’t a prerequisite at Orudera Middle School, not by any means—it’s more of an enhancement, the little asterisk of gamma radiation. Not positive or negative... supercharged. Powerful. 

Dangerous.

Katsuki stares at Deku across the chessboard. The clock ticks in the empty room.

It’s not that Katsuki’s a chess nerd, or a nerd at all. Nerdiness is for useless Deku, with his nose in his books. He’s always scribbling something in those notebooks of his, lugging big textbooks in his bag that aren’t even for school.

“Make your move already,” Katsuki hisses at him.

Deku is many things: irritating, twitchy, sweaty. Katsuki calls him many insults, but not dumb. Deku’s anything but stupid. Katsuki’s loath to admit it, but he’s the only person who can come close to Katsuki’s genius in this sad excuse of a school.

Katsuki’s going to be the best, but it’s lonely at the top when everyone is so far below. Chess club is the best way to meet Deku discretely—the club is located in the wasteland of a physics classroom. Understandably, it has no other members. The people in eighth grade are more interested in talking about sex and partying than learning how to execute the Queen’s Gambit.

As his starting move, Deku pushes his pawn forward with a shaking finger. 

It makes Katsuki angry. Honestly, everything Deku does pisses Katsuki off. At least Deku’s firm in his resolve: tentative, but unyielding. He never undoes a move. Katsuki grudgingly respects that, but everything Deku does ignites him.

Katsuki slams his pawn forward a square. A bead of sweat rolls down Deku’s temple. They begin in earnest.

It’s intense. Their games always are—everything involving just them is always ramped up to the highest degree. Katsuki’s never been calm a day in his life, and Deku’s never done anything half-assed, so he matches him not in anger, but in intensity.

The only sounds are the squeaks of Katsuki’s chair as he shifts, Deku’s dirty sneakers scuffing the floor, and the clack of pieces on the board.

It’s too quiet, but Katsuki feels alive. He attacks with his rook and Deku counters with a complicated maneuver using his knight and pawn. They continue to battle slowly, turn by agonizing turn.

Katsuki furrows his eyebrows. Deku wipes at his forehead with his shirt while Katsuki drags his sweating hands along the pants of his uniform.

The clock hits half after, then quarter to. The pauses between their turns now take minutes. Katsuki’s not in the greatest position right now—Deku doesn’t have a clear way to win, but Katsuki has no way to counter. Vulnerable.

Katsuki reminds himself that he’s never lost. He can’t lose, and there’s no fear of doing so. If he’s never lost before, that’s because he doesn’t know how. Or rather—Katsuki always knows how to win. He’s smart, powerful. He was supposed to be born with only the best: good looks, a rich family, perfect grades, a huge house with a pool. He throws away love letters on the daily. They’re all written in different handwriting, but there are repetitions and rarely ever signed.

Deku takes his turn, and Katsuki finally finds a way to counter.

Life is good. And when it isn’t, Katsuki has his own personal punching bag who shuts up, takes it, and never tattles. Deku is many things, but he isn’t dumb and he isn’t a snitch.

Katsuki’s going to apply to Yuuei when applications open, use his brain instead of brawn to place first in the entrance exam, and every exam and practical thereafter, and blow everyone away. 

He has it all.

Deku has nothing. He comes to school in a second-hand uniform because his dad left and his mother can’t keep a goddamn job. Deku gets bullied mercilessly, not only by Katsuki but the rest of the grade. He’s a joke to everyone even though he isn’t the only quirkless kid. Deku sits alone at lunch because everyone refuses to talk to him, and the few accepting types quickly get scared off by Deku’s ceaseless muttering. At least Deku doesn’t raise his hand in class anymore and Katsuki doesn’t have to hear his voice.

And yet… Deku pities Katsuki. He shouldn’t. Katsuki hates it. He doesn’t need Deku’s fucking pity to succeed.

Deku makes a few strange consecutive moves, moving some of his pieces to the side of his board and bringing two others around. These are his death throes, and Katsuki relishes them.

The clock reads ten past five.

Katsuki takes great joy in isolating Deku. He thinks that when Deku is suffering is when Katsuki’s most happy.

Unfortunately, the effect of separating Deku from everyone else except himself has an unintended effect, and the person Deku interacts with most is Katsuki. 

He’s always viewed Katsuki in the highest regard—rightly so, but now Katsuki’s become the sole focus of his attention. With any other person, a focus of that intensity might be worrying, but Katsuki brushes it off. It’s Deku. It’s not like Deku can do anything to hurt Katsuki.

Katsuki makes a move.

Deku says: “Checkmate.”

There’s no reaction in Katsuki’s head at first. He’s planning his next move, and the subsequent one and the one after that—then it registers because he thinks that Deku just checkmated him, but that’s impossible. But Deku is almost as good at this game as Katsuki is, so Katsuki will give him the benefit of the doubt. His eyes rove the board, mentally retracing the moves, does it again to check. Eventually, he comes to one conclusion.

He lost.

He, Katsuki Bakugou, lost.

And that is impossible, and moreover unthinkable. Katsuki doesn’t lose, much less to Deku. Deku always loses, and Katsuki always wins.

How dare you, Katsuki thinks.

He doesn’t say anything. He flips the board in Deku’s face and walks out.

There’s a thunderstorm in his mind. It whirls and spins. He’s no longer focused on the game, because it’s not about the chess. Deku bested him, beat him, trounced him, and that’s humiliating but also terrifying. Now that he’s done it once, he can do it again.

Katsuki stumbles his way back to the classroom to pick up his bag, having left it there in his eagerness for the match. Deku thought ahead and brought his with him. so he’s probably on his way home. That’s fine; it just means that Katsuki can nurse his wounds in peace.

His backpack sits heavily on his shoulders. Katsuki’s strong because he’s training to be a pro hero despite the odds, but he’s tired. Deku’s win (Katsuki’s loss) hit him much more than he expected—he never entertained the notion that Deku might somehow manage to beat him.

That’s just—impossible. Unthinkable. Deku isn’t stupid, but he’s weak. Katsuki’s strong to begin with and only continues to get stronger, while Deku sits off to the side, scribbling his notes and mumbling.

The sun begins to set as he trudges home. He wonders if one day—after he’s gotten out of this shitty city and family and house—he’ll remember the streets he passes. 

Every time the fading lights glint off a building or a car parked out in the street, Katsuki turns west to stare at the skyline. The clouds are tinged in flaming pinks and reds. Katsuki usually can’t find a reason to stare at ordinary things, but he can admit that it’s beautiful. It’s hard to find beautiful things in his life these days, but the sunset is something that always takes his breath away. He wishes that he could go to the horizon and take it for himself. 

Katsuki’s read about mythology in various religions, and they all mention the sun: Amun-Ra, Sol, Helios in his chariot. All personified, all beautiful.

Maybe someone could bring him the horizon. Katsuki snorts. He must be more exhausted than he thought if he’s entertaining letting someone help him.

He reaches the street where he lives and walks over to his house. He prepares to key open the door, step inside, and kick off his shoes. His mother would yell at him, but she’d have to be there to see the state of disarray first.

Katsuki’s parents are always busy, but it’s not like Katsuki cares. It’s better when they aren’t home, anyway. He can do whatever he wants, whenever he wants. The house is always silent and Katsuki studies best in quiet. It’s a good arrangement. He learned to cook for himself—the old hag obviously wasn’t going to leave him leftovers in the fridge.

He checks his pocket for the house key and finds it empty. He groans, because the hag won’t give him another and tell him to use the spare. He bends down and checks inside the ceramic frog next to the door where the spare key is located. His fingers scrape the rough insides. Katsuki picks up the frog, turns it upside down, and shakes it. Nothing rattles inside. He peers into the space and sees only emptiness.

Either Katsuki forgot to put the key back inside the frog and accidentally left it inside, or his parents are home. He’s not sure which one he prefers.

“Damn it,” he says, because if both keys are misplaced then he’s locked out of his goddamn house. “Shit!” He kicks the door out of frustration, and tries the knob, and freezes when it turns.

The door is unlocked.

His parents don’t always lock the door, so this is no cause for alarm. But they don’t do it often. Katsuki turns the knobs, pushes the door open slowly and quietly, just in case they’re home. 

He steps over the doorway. The house is dark. No one’s home. Katsuki lets out a breath. Through a stroke of fortune, he must’ve actually left the key inside and left the door unlocked! His mom would’ve killed him if she knew the house was unlocked and unattended all day, but what she doesn’t know won’t hurt her. 

Katsuki puts down his backpack and it thumps down on objects that fall over. Katsuki curses under his breath and hits the light switch, hoping that he didn’t crush anything important. 

 After he straightens out the mess, he walks down the hallway and turns towards the kitchen. It’s late and he’s hungry. He turns on the kitchen light and dives for the fridge.

“You moved your spare key,” someone says. “It’s usually under the doormat.”

“Holy fuck!” Katsuki screams. He turns around and there’s no possible way he’s going to fight the odds to be a hero, because there is a man sitting on the counter. The stranger’s arms grip the sides, kicking his legs casually, and Katsuki walked right by him. 

Katsuki will hate himself for the rest of his life, but his first thought is that the man is beautiful. He’s sitting nonchalantly on Katsuki’s counter, but Katsuki’s gaze is immediately drawn to the man’s eyes. 

They’re vibrant and intense, so green they contain a jungle bursting with life. They stare right back at Katsuki, and Katsuki feels like the man is looking at him and through him; reading him down to his genetic sequence and to the core of everything he is. The effect is simultaneous to a deer in headlights. Katsuki is so enraptured by this man’s perfect eyes that for a third of a second, he’s rooted to the place as he drowns.

Then the man blinks, and the moment is gone. Katsuki lets out a yell of rage and runs forward. He grabs the intruder by the front of his shirt with one hand. The other is lifted in the air and forms a fist. “Tell me what you’re doing here or I’ll beat your ass! I’ll do it!”

The man holds his hands up, laughing. “Hold on a second! I know I’m intruding, but don’t you recognize me?”

“Tell me who you are right the fuck now!” Katsuki shouts.

“Now just wait a second,” the man says. His smile creates wrinkles around his eyes. “Take a good look. I’m sure you know who I am.”

“What do you mean?” Katsuki’s so thrown off-kilter by Deku’s win, his own loss, and this stranger completely disregarding the fist in his face and his fucking eyes that Katsuki’s having trouble processing simple visual input. “Who the hell are you?”

“Don’t you already know?” the man hums. “You should definitely know who I am, Kacchan.”

In that instant, everything explodes. Not literally. In fact, Katsuki immediately lets go of the man’s shirt and nothing else happens. But something deep within Katsuki twists and combusts. It’s like not knowing where he is and having his mental location snap back into place—dizzying and so right.  

There is an overlay between a boy and a man. Katsuki’s brain compiles them and they make sense but they also don’t, because this man in front of him must be an older version of Deku. But that’s a big fucking problem, because—

Because this is Deku, and he is beautiful.

“Deku?” Katsuki breathes, conflicted. He always wants to smash Deku’s stupid face in because it’s twitchy and sweaty and gross, but he kind of doesn’t want to do that now. “Izuku?”

“Hi, Kacchan,” Deku says kindly. “Call me Deku, please.”

“You want me to call you Deku?” Katsuki says stupidly, hating what he’s about to say next because for some reason, he doesn’t want to see Deku’s face frown. “It’s, like, an… insult. You realize that, right?”

Izuku beams at him. “I think it’s cute!”

Katsuki is hopelessly confused, because the energy radiating off of the Izuku isn’t hostile. It’s by and large positive—and, if anything, a little smug.

That… doesn’t really fit the vision of Deku that Katsuki has. Deku is small and shaky and scrawny. Izuku is mature and big and confident. The only constant is that for some reason, they’re both happy to see Katsuki.

A part of Katsuki wonders why he isn’t chasing this stranger out of his kitchen. But Izuku can’t be lying about his identity, even if his behavior is different. How can Izuku be so different to Deku and yet the same? His body and the way he carries himself are different.

The eyes are different too, but somehow the same. Is it because they’re in a face that Katsuki doesn’t hate on sight? Would he be this infatuated with Deku if Deku was conventionally attractive?

Katsuki knows he’s staring at Deku but can’t seem to stop. He keeps comparing the two of them, but it’s like dividing by zero and it refuses to compute. He snaps out with the first thought that comes into his mouth, which is unfortunately: “When the hell did you get so goddamn muscular?”

“You’re one to talk,” Deku says to himself. “After all, Kacchan is always beautiful.”

Damn right he is. But for the first time, Katsuki thinks that Deku may be a little insane. The way Deku stares wistfully at him signifies… something. Deku’s eyes and the way he looks at Katsuki like he’s his whole world stands for something; Katsuki often doesn’t see the symbolism until someone else points it out.

Deku’s gaze is too intense. It’s like Deku wants to eat him alive, but that’s weird. There’s an emotion on his face that twists it into something else and darkens his eyes. Katsuki knows the definition of “lust” in theory, but seeing it on Deku’s face...

Katsuki’s ears burn, so he reacts accordingly when he doesn’t know how to process something: he pushes it away. “Get out of my house!”

“I don’t think I will. It’s fun to see you all flustered.” Deku settles back on his hands. “It’s been a while.”

“Go bother someone else,” Katsuki sputters. “Deku’s annoying, but I’m sure you could tolerate him, since you’re apparently the same… person? Although”—Katsuki laughs bitterly—“he’d probably just tell you to find Kacchan!”

“Kacchan’s dead,” Deku says softly. Something dark flashes in his expression, like the sun passing through a gap in a cloud. “Most of them are.”

“No, he’s not,” Katsuki says, and leaves the second part alone. This Deku is sunnier than his, but Katsuki has the strangest feeling that something lurks under the surface. The Deku that he knows wears his heart on his sleeve. “And now I’m speaking in the fucking third person. I guess you’re just like Deku, because you’re both stupid. I’m obviously right here and not dead.” Then he pauses. “Them?”

Deku gestures towards Katsuki. “You’re you, or one of you, anyway. Did you really think there wouldn’t be others?”

“I—” Katsuki says, and hates the phrasing but doesn’t know how else to say it. “Is yours dead?”

“He was my first,” Deku says, almost to himself. “He was mine.”

Katsuki doesn’t have time to unpack that, but the man doesn’t give him an opportunity to.

“Tell me, Kacchan,” he says, looking Katsuki up and down slowly. “Do you know anything about quantum physics? I don’t expect you to. You’re a little young to be able to understand concepts that complicated.”

Sometimes Katsuki goes on forums and websites and researches to his heart’s content. It’s interesting, digging into whatever catches his interest. He reads all night, and it’s an escape of the best sort: from his mother, his posse, and the expectations that he’s built. No one else exists for a while. The night is the best time—the darkness wraps quietly around him, as Katsuki loses himself in his own little world.

It’s only Katsuki clicking on his computer, even though it used to be Katsuki and Deku hidden under a shared blanket. 

Katsuki is good at computers but not so much at people. Maybe it’s because he hasn’t been exposed to anyone genuine. (Deku’s always been authentic. Even though he pities Katuski, he’s honest about it. Katsuki angrily pushes that thought away.)

Besides, it’s always Deku that’s been the nerd. Deku carries around textbooks with math that’s beyond their teachers—they’re the only books Katsuki doesn’t throw into the toilet and flush. He’ll ruin Deku’s hero notebooks because they are Deku’s which means they’re inherently flawed, but destroying books filled with pure, clean physics strikes him as wrong. Katsuki does things that he sometimes regrets, but even he has lines that he won’t cross.

Katsuki bares his teeth. “I know some.”

“Would you like me to teach you some more?”

“No, you smug asshole.” 

Katsuki does, but not for the sake of science. There’s something to this Deku that fascinates Katsuki. He’s obviously hiding something, because he’s an older version of Deku and hasn’t said how or why. Deku probably has a reason to hide it, but if Katsuki acts like he doesn’t want it, Deku will appreciate the challenge and give Katsuki what he wants. It can be a power play and a reward.

Technicalities aside, there’s something to this Deku that his Deku doesn’t have, and if Katsuki is honest with himself, it’s probably the muscles. Katsuki never thought himself shallow, but he keeps running his eyes over Deku’s obvious bulk: shaped and toned from the shoulders to the calves.

Deku’s also acting like he’s superior to Katsuki, which is enraging but also makes him feel... unusual. His Deku is too wimpy to actually push back in words, instead using small actions to undermine everything Katsuki does. The direct opposition from this Deku isn’t altogether unpleasant.

Katsuki comes to the realization that his dick is chubbing up in his pants. He’s a teenager so it’s not like this is strange, but it’s never happened in the context of Deku. He feels slightly disgusted with himself, and shifts in place.

“Let me teach you,” Deku says, and Katsuki blinks back to the conversation. Quantum physics, right. “Education is important, and Nise in particular always sucks.” He pats the space next to him. 

“I go to Orudera. Nise got renamed a few years ago.” Katsuki hops up next to him and says, “I want to know how you got here.” 

“Sure,” Deku says, green eyes oddly intense. “But you have to earn it, okay?”

“Of course I will,” Katsuki says. He and this Deku are on the same wavelength. “I get what I want when I win.”

“All right. Listen closely. I’m not going to bore you for too long, because who the hell wants to listen to boring quantum mechanics, but this is important.” Deku laces his fingers. “I’ll start from the bottom. You probably will want to zone out at some point, and that’s okay. Your brain isn’t developed yet. Think of processing the information this way: let it wash over you. It’ll all make sense by the end, even if you don’t get it at first.”

“Get on with it,” Katsuki grumbles.

“A wave function,” Deku says, “is defined as a variable quantity that mathematically defines all the possible observable states of a quantum system. The value of the wave function of a particle at a given point in space and time is related to the probability of various possible locations of a particle.”

So far, so good. Katsuki can do this.

Deku hops off the counter. “Under realism and determinism, if the wave function is regarded as ontologically real, and its collapse is entirely rejected, a many worlds theory results. The Many-Worlds Interpretation, or—”

“MWI!” Katsuki blurts, shocked. Deku is always muttering about how it’s completely flawed, and most of it passes over Katsuki’s head.

Deku delightedly claps his hands. “Yes, MWI! It’s an interpretation of quantum mechanics that asserts that the universal wave function is objectively real, and that there is no wave function collapse. MWI suggests that we live in a near-infinity of universes that are superimposed in the same physical space, but are mutually isolated and evolving independently.”

“In Japanese?”

“It means that all possible outcomes come to pass in some universe.”

“Ah.”

“Until the wave function collapses, according to MWI, there isn’t a ‘greater degree of reality’ for any possible state.” Deku waves his hands, excited. “It’s not that it’s one or the other: the wave function lets them all exist. Take the paradox of Schrodinger’s cat—”

“I already know what this is,” Katsuki interrupts.

Deku stops and sighs. “Kacchan, you’re smart or whatever, but you actually need to know this. Will you let me explain?”

Katsuki wilts and tries to hide it. “Fine.”

“You put a cat in a box with a radioactive isotope, which has a 50% chance of decaying. The wave function is a mathematical value that states that there’s a 50% chance of both life and death. If it decays, the cat obviously dies.”

Katsuki rolls his eyes. “Obviously.” 

“When we make a measurement, we get one result out of the many that quantum mechanics offers. Wave function collapse was demanded in order to connect quantum theory to reality. Therefore, physicist Hugh Everett III proposed MWI.”

“God, not a history class,” Katsuki groans. 

Deku laughs. “Everett proposed that it’s our concept of reality that’s at fault—thinking there’s a single outcome of a measurement. He said that all of them occur, and we only see one of those realities, but the others have a separate physical existence as well.” He stops. “Now, Kacchan, I’d like you to do something for me.”

“Now?”

“Yes.” Deku hops back onto the counter and sits next to him. He puts a hand in the middle of Katsuki’s back and pushes him right off. Katsuki squawks. “No, no; none of that. Face me.”

Katsuki complies, growling, “This better be good.” 

“It hopefully will be. What happens next depends on it.” Deku’s hand goes to his belt buckle, and Katsuki’s eyes immediately widen.

“It’s okay, Kacchan.” Deku puts his freckled hand on the top of Katsuki’s head, and unzips his trousers with the other. “You know I really am Deku, right? I’m not lying.”

Katsuki nods.

“So I have no reason to hurt you—I’d never hurt you if you were good enough. Now, I want you to answer me, and to do it honestly: do you want this?”

“Want what?”

“Do you know what a blowjob is?”

“I—” Katsuki blusters, face burning. “What does that have to do with anything?”

“Talking about science can get a little repetitive for me, especially since I’ve done this before. I need you to understand because this’ll determine if you can help me leave, but I want to pass the time. It’s not that hard to do. Lots of people do these things for each other to make them feel good. I know you’re used to hurting your Deku, and you should feel guilty about that.”

Katsuki is suddenly interested in the ground.

“I know that deep down you have empathy, because even though you tell yourself that you’re a big boy and that you don’t have silly emotions, that’s just not true.”

“Stop talking,” Katsuki says quietly.

“Think of this as kind of a redemption. By helping me get home and making me feel good, you’re helping both me and your Deku. You’ll be doing this sort of thing a lot in the future. I’m here to instruct you on what to do and how to do it.”

“This is sex,” Katsuki says, getting angry. “You want me to have sex with you.”

“Yes,” Deku says plainly. “I promise I’ll make you feel so good later. But right now, I need you to stamp down that temper that keeps getting you in trouble and use your drive to help me instead.”

Katsuki wants so badly to tell him no. A part of him is screaming that he’s crazy and to slap the expression off Deku’s face. And what the hell was that bit about hurting him if he’s not good enough? That should scare him, because Deku looks big enough to actually do damage, but he’s quirkless. If push comes to shove, Katsuki could always take him down. 

“I won’t do anything you don’t want me to do,” Deku says. “But Katsuki—I know you. You want this. You’re scared, and that’s okay. We all have things we don’t want to try in case we don’t like it. I can assure you that you’ll like this very much, because you’ve always liked to do it before. It’s perfectly all right to be nervous—but are you seriously going to back down because you’re scared?”

The reality is, the last thing Katsuki wants to do is put his mouth on Deku’s dick. However, a change underwent in the duration of Deku’s speech. His back straightened, his hands tightened around the counter, and there is a distinct tent in his pants. That makes Katsuki uncomfortable, and to be honest, a little shaky. 

Katsuki trained hard to being able to defend himself, but he isn’t quite there. It burns to admit it, but this Deku could take him down easily.

Before he can voice anything, there’s a dick in his mouth. Deku guides him down firmly when Katsuki hesitates, and Katsuki closes his lips around it and gags at the taste. It’s… heavy, thick with sweat and musk. Katsuki’s mouth waters not because it tastes fantastic but rather because there’s a huge fucking object in his mouth. He swallows to avoid spit dripping from his chin. 

Katsuki tries to pull away. Deku’s hand tugs his hair and holds him down and Katsuki makes a noise of protest. Deku says, “Sh, Kacchan. Just hang on for a bit, okay?”

Katsuki feels so stupid. He’s never done this before and doesn’t know what to do. Sure, he gets horny sometimes, but he’s never gotten to the point of watching porn. For some reason, it grosses him out: the few times he tried, he was overcome with this odd repulsion and slammed his laptop closed. Now he’s inexperienced, and he could play it off because he’s young, but that’s never stopped Katsuki Bakugou before.

For the first time in his life, he doesn’t know what to do. He looks up to Deku for guidance, and sees Deku staring at him so intently that Katsuki doesn’t want to disappoint him. Katsuki’s nervous and doesn’t know what to do. How can he be the best if he doesn’t know how to be good? 

Katsuki struggles not to gag on Deku’s cock, and feels rather than sees that Deku is cut, which is odd but he doesn’t remember why. He isn’t given much time to think about it, because Deku starts to talk. 

“Everett described a ‘universal wave function,’ which is the entire universe and all possible realities contained within it.” Deku runs his hands through Katsuki’s hair, and Katsuki shivers. “The universal wave function begins as a superposition of all possible states of its constituent particles. As it evolves, the superpositions break down, creating distant and isolated realities. In summary, the worlds aren’t created by the measurement, they’re separated.”

Katsuki’s too tall to stand and too short to be on his knees. He tries to pull away again, pushing off of Deku’s thighs, but Deku’s hand is still in his hair. The other comes to Katsuki’s back and rests there. When Katsuki stops trying to straighten up, the hand starts stroking up and down. Katsuki should hate this, because it’s like he’s a goddamn dog or something, but it—feels kind of nice. It’s more that Katsuki’s never had someone hold him down and in place before, and while he hates it, it’s also… different. So he half-crouches there with Deku’s cock in his mouth, and he listens.

“The common misinterpretation of MWI is that the realities are viewed as branches on a tree. The trunk is the original universe, and the “decision” itself is never made… because both outcomes occur. The trunk splits, and the branches continue outward on their separate timelines with no influence on each other. That’s not strictly true, even though Everett wrote it in his thesis.”

Finally having mercy, Deku grips Katsuki’s head by the hair and moves his head up and down. Katsuki gets it quickly from there, and thank god, because now he can actually do something. He’s a fast learner. Deku removes his hands from his hair and back and places one on the back of Katsuki’s neck. The other caresses his cheek.

“By the way,” Deku says, “MWI is completely different from the multiverse theory, which states that other universes, born in separate Big Bangs, have always been physically disconnected from our own.”

Deku pauses. The only sounds in the room are the soft sounds of Katsuki on his cock. Katsuki is disgusted with himself, but it’s muted.

“Some physicists wonder if the wave function is necessary for particle diffraction. The double-slit experiment proves that light demonstrates both characteristics of waves and particles. The experiment was first performed by Garner in 1801. In 1927, Davisson and Germer extended wave-particle duality to atoms and molecules.”

Katsuki pulls off his cock to say, “I didn’t think I was getting three history lessons today.”

“Three, I get it. Because of your class and the two times with me.” Deku pats his head like a dog. “How clever. Now, in a basic version of the experiment, a light source, such as a laser beam, is shone on a plate with two slits. Because light displays a wave nature, it will demonstrate interference—constructive and deconstructive—resulting in bright and dark ‘bands’ on the screen. This behavior wouldn’t be observed if light was only particulate.”

Shut up, Katsuki thinks. Deku talks with a particular type of grating confidence. Granted, Deku usually knows what he’s talking about, but it’s marginally less irritating when he’s nervous about it.

“However, the light shows particle behavior as well: the light is absorbed at the screen at discrete points as individual particles rather than waves. The interference pattern appears via the varying density of these particles on the screen—ah, fuck.”

Katsuki can multitask fairly well and he learns that he can do various things with his tongue. He finds that he wants to break Deku’s composure and finds out what’s behind the facade. Break Deku to prevent him from breaking Katsuki first.

“If the”—Deku pants—“if the diffracting slits are considered as classical objects, which is an option modeled by physics before quantum mechanics: having definite position and location, with movements governed solely by Newton and Maxwell’s laws, shit”—he pulls Katsuki’s hair with both hands and grips tight—“then the wave interpretation is necessary. But if the slits are considered physically—quantal objects exhibiting collective quantal motions—then the particle and wave characteristics are equally valid.”

Katsuki bobs his head, wanting for Deku to lose it. Deku reacts exactly how Katsuki wanted—he groans heavily, and his hips jerk forward. Katsuki, unfortunately, discovers he has a gag reflex. Deku pulls back, as Katsuki goes back down all the way, chokes, and grips Deku’s waist with his hands in retaliation.

“Oh, yeah,” Deku groans above him, low and heavy. “God, suck it. Suck my fucking dick, Kacchan, I want it so much.”

Katsuki pulls off. “Finish it,” he says, because he’s always liked to play with fire, and he started this, and he—he can’t believe he wants Deku to—

“The d-double-slit experiment,” Deku says, getting increasingly desperate by the way his hips fuck into Katsuki’s mouth, “has become a classic thought experiment. It demon-demonstrates the fundamental limitation of the, of the observer’s ability to predict experimental results.”

Katsuki feels Deku’s cock twitch on his tongue, and this is it. Deku is going to come, and Katsuki’s going to be the one to make him do it.

 “It’s a phenomenon that can’t b-be explained in classical ways.” Deku shudders; pulls his dick out of Katsuki’s mouth and jerks it. “It contains the only mystery—the heart—of quantum mechanics—”

Katsuki has maybe a second to think, Oh, shit! before Deku’s coming all over him. It gets everywhere: his face, his neck, even his uniform.

Katsuki coughs as he stands up to his full height and uses his shirt to wipe the come off his face. “Jesus Christ, it’s like a fire hose.” 

Deku’s smirking at him in a way that’s kind of mean.

Katsuki grits his teeth and has to look away so he doesn’t actually punch Deku in the face. He goes to the sink and washes off his face. “Asshole,” he says petulantly. “I can’t believe you came on my fucking face. You so owe me for this!”

Even though Katsuki can’t see Deku’s current expression, he guesses that the smirk is still plastered on Deku’s face. Strangely, it feels like Katsuki doesn’t deserve it, because behind that smirk must be a smile. Although smirks usually don’t mean happiness, they’re goading and cruel and—Katsuki must be misinterpreting this, because why would Deku be mean to Katsuki? Even stranger, it felt like it was being directed once again through him, almost to someone else. Katsuki waves it off because it was only a brief glimpse, and he’s trying to get the come off of his face.

And—wait a second. Katsuki’s hands still on his face. He was so caught up with being weirdly repulsed and attracted to Deku that he completely forgot his original plan: to get Deku to talk about where he was from. Now that he no longer has a gross dick in his mouth, he snatches a towel and wipes, his face off, about to interrogate him. 

“What was the point of this?” Katsuki rasps, and ow, his throat hurts kind of a lot.

“Oh, you want a reason behind this?” Deku snorts a little. “I already explained. Don’t tell me you forgot that quickly.”

That stings. Katsuki frowns. 

“The point of this was to show you that no matter what you do, there’s always a version of you that does something different,” Deku tells him. “With MWI, it means that virtually every event will come to pass. So what was the point of the blowjob, you ask?”

Katsuki nods.

“There really wasn’t any point to it. It was mainly to see what you could do and how well you process information. I don’t think anything that I said went into your head, did it? Tell me about wave-particle duality.”

Katsuki is silent. While he learned how to give a blowjob on the fly, Deku’s words mostly went over his head. He strangely wants to apologize, which is completely screwed up, because Katsuki never apologizes to anyone. But Deku must’ve known that. Was he setting Katsuki up for what he defines as failure? And how does that relate to MWI?

Deku’s waiting for Katsuki’s response. Katsuki almost winces, so he tries to direct Deku to answer his internal question. “So according to MWI, now there’s a universe where I didn’t, uh...”

“Yes.” He turns around to see Deku tucking himself in, pulling up his pants, and zipping up. “But that’s a bad way to look at it. Let's assume that you're gagging for my dick in your mouth and you're about to say yes. MWI tells us there's a reality where you're not gagging for it and don't do it. There's also a reality where you're not gagging for it but you do it anyway. And one where you want to do it but don't. There's a reality where you don't do it but then I force you to.”

It’s a little crude and the last implication confirms something that Katsuki doesn’t want to acknowledge, but the explanation works and Deku continues.

“The moment I asked you to suck me off, an infinite number of universes were created. You said yes. You could’ve said no. You also could’ve said you liked rubber ducks, and the two of us might’ve gone upstairs and taken a bath. But what I’ve found is that the totally implausible choices occur less often. There are many more universes where you either said yes or no.”

“How can there be ‘less’ of an infinity?”

“That’s a good question, though off-topic. Think of it this way: if you took a random sample size, then there would be more of you responding in the negative or affirmative than any other ‘random’ action. But that stuff is boring, so... what do you think of your Izuku? Be honest.” He waggles a finger. “I’ll know.”

“I fucking hate him.” Katsuki coughs. “He’s nervous and twitchy and quirkless.”

Deku doesn’t exactly recoil, but a shadow passes briefly over his face. “You don’t really mean that.”

“N—” Katsuki clears his throat, goddamn it. “No, I really do.”

It’s true: Katsuki has no positive feelings for Deku. He’s small, annoying, and sweaty. Creepy, a loner, the school’s resident misanthrope. Katsuki would be ashamed to be associated with him.

Deku asks, “Then why’d you go along with sucking my dick?”

That’s the root of the problem: Katsuki doesn’t know. He hates Deku more than anything else, but this Deku is somehow different. Why? Why is Katsuki letting him stay?

“Deep down,” Deku asserts, “you have feelings for Izuku.”

“I don’t love Deku.” Katsuki recoils, and hacks out his lungs again. “I don’t even like him!”

“I know you do.” Deku lifts up his shirt. Old burn scars stretch across the muscles of his abdomen. “But lovers don’t hurt each other.” He lets the fabric fall back into place. “You hurt Izuku, don’t you?”

Katsuki shrugs. Not as much as he used to. Katsuki used to turn on Izuku with his fists and strength, beating him until he was black and blue and shivering in fear. Izuku let him because he had no other choice.

Now, it’s less of what Izuku is and more of what he represents. Katsuki thinks if they had both been different, they could’ve been friends. 

Deku’s pensive. Katsuki wonders what he’s thinking.

“I love Kacchan,” Deku says finally. “Maybe too much. But it’s better to have loved than to have never loved at all.” 

“But I’m right here.”

“I know,” Deku snaps out before he visibly reigns himself in. “And that’s the problem, isn’t it?”

They stare at each other in silence, because Deku’s being unnecessarily cryptic and isn’t elaborating further. Katsuki is rapidly losing patience with him and also kind of scared, because he did what Deku fucking told him to do, didn’t he? Where’s his goddamn reward? 

“So...” Katsuki eventually says, masking the shakiness in his voice, “how long does it usually take until you’re back?”

“No idea. It’s different every time.”

“That wasn’t your first time?”

“No,” Deku says.

It was mine, Katsuki thinks. “So what now?”

Deku shrugs. “Now we wait.”

“That’s supremely unhelpful,” Katsuki says, choking on nothing. Deku goes and gets him a glass of water. It’s concerning that he knows where everything is.

“It’s not like you can do anything,” Deku points out, handing the cup over. “You’re barely a teenager. I’m an adult, but all of my money is invalid and my card won’t register on any of your machines.”

“We have ATMs,” Katsuki says after taking a long drink. It helps.

“What are those?” 

Katsuki frowns at him, and returns to sit at the desk. “You’re not that old.”

“Yeah, I’m joking.” Deku scrubs his hair. “I was just planning to go to the police station and go find Tsukauchi. I’d go to one of our class’ agencies, but those haven’t been established yet, right?”

Katsuki feels his eyes go wide. “Hero agencies? Do we actually manage to do that? How? I thought that quirkless—”

“I can’t tell you that either,” Deku says, and Katsuki frowns. “Although, maybe I can. If this is a separate timeline or a different universe entirely, then it probably won’t matter what I tell you. Just me being here and talking to you has probably changed your life irrevocably.” He laughs to himself too hard while Katsuki stares at him until Deku eventually manages to stop. “We end up being pretty important.”

“To what?”

“Oh—to, uh, everything. It’s impossible to explain what we went through in high school because I’d need a few days. Did you know that there are history textbooks being written about me? In a few years, kids will learn about me and 1-A in school.”

“What the hell is 1-A?”

“It was the class we were in when we went to high school,” Deku says. “There were twenty of us. Twenty-one later on, and then a few got killed off later for various reasons. “Here's a life lesson: as you get older, you’ll learn that quirks are not as great as people say they are. They’re not powers, and they’re not blessings. They’re a part of you, like an arm or a leg. Most of the time they assist you and aid your quality of life, but sometimes they grow a tumor or are deformed. And do you know what you do with cancers, Katsuki?” Deku’s eyes are flint. “You cut them off, and if they grow back, you burn them.”

“But I don’t have—”

“Quirks are fun because they’re new and interesting. They’re the equivalent of clocks to you and me. We take the gears apart and disassemble the structure to learn about its mechanics, and if the urge strikes us, we put them back together. Otherwise, when we’ve gotten all the information and analyzed everything we can, we leave. Otherwise, you’re never going to be done. There’s an infinite scroll feature on the list of things we need to do. People burn out. They’re too bright and they work too hard and then poof” —Deku gestures with his hands—“they’re gone. And it’s like they never were. It’s like they never existed.”

“Quirks are good,” Katsuki says.

“No, they’re not,” Deku answers firmly. “They’re really, really not.”

They stare out the window together. The setting sun blazes orange on the horizon. Eventually, even though all he wants to do is get Deku out of his sight because his instincts are telling him that something is off, Katsuki asks, “Do you wanna stay at my house until you go home?”

“You’d really let a stranger into your own home? Didn’t Mitsuki ever teach you anything?”

“Hey,” Katsuki says, irritated. “First off, you’re Deku—”

“A version of him, at least,” Deku says. 

“—and secondly, don’t talk about my mother that way!”

“Damn.” Deku stares at him, and it’s almost pitiful. “You forgot what your parents did to you?”

“I didn’t forget.” The words taste sour in his mouth. He doesn’t believe himself. He doesn’t think he’ll ever be able to forget the silence of an empty home.

“Then I guess you’re better than I’ll ever be.” Deku stands up and stretches. “Is the offer for crashing at your place still up, or am I sleeping on the streets tonight?”

Well, if he worded it that way. “I guess a future version of someone I despise is worth it.”

Deku smiles. “Great.” It’s fake.

Katsuki pulls out packaged noodles, vegetables, and soy sauce, and starts to make a simple meal. “I’m hungry,” he says. “Aren’t adults supposed to know how to cook?”

Deku sits down at the counter and watches him.

“No,” says Deku. “There’s usually been someone to cook for me.”

Katsuki doesn’t know what to say to Deku’s vagueness and keeps quiet instead. The house is filled with the sound of Katsuki banging pots around until Deku finally says, “Kacchan,” and nothing else. 

“What,” Katsuki says as he fills the pot with water and sets it on the stove.

“There are many interpretations of quantum mechanics, as we can see,” Deku says.

“This again?” Katsuki groans. 

Deku dead-eyes him. “Fine. I won’t say it.”

Katsuki feels his mouth twitch downwards. He enjoys being difficult, but he’s irritated at both of them: Deku for talking, and himself for being interested in what Deku has to say.

“Ask me about interpretations of quantum physics,” Deku prompts. “You know you want to.”

After a significant pause of maybe two minutes, during which he dumps the noodles into the pot and waits until the water has boiled, Katsuki says, “I don’t want you to tell me about quantum physics. That shit’s boring. I want you to tell me how you got here.”

“That’s my quirk.”

Katsuki is in the middle of aggressively cutting the vegetables and dumping them into another pan when he yells, “You were complaining about how quirks were so bad but you fucking have one?” and almost scatters mushrooms everywhere. 

He slams down the pan and runs over to Deku, poking a finger right into Deku’s stupid muscular chest. “Stupid fucking Deku has a quirk? But—how? You don’t have a quirk, that’s your thing! I’m the best, and we’re quirkless. That’s how things are! You can’t just have a quirk! The extra toe joint—explain that to me!”

“Science changes.”

“What!? That’s your excuse? ‘Science changes’!? Science changes, my ass!”

Deku looks at him, bored. “You should turn on the heat.”

“What?”

“The stove.”

Fuming, Katsuki stomps over and turns it on. “You better tell me what your quirk is right now or I’ll kill you!”

Katsuki’s angry beyond belief but also hurt, which is surprisingly unpleasant. When they were kids, Katsuki and Deku always promised each other that they were the first ones they’d tell that they had quirks—before the classmates, before their parents.

Kacchan is so cool, he said. I can’t wait until I get my quirk!

I bet it’ll be less cool than mine! Katsuki said.

As long as we’re heroes together, Deku said, then I don’t care what my quirk is.

It’s funny how things work out.

“My quirk?” Deku says flatly. “It came in later. You know how some quirks only get activated by a specific set of events?”

“Well, tell me what it fucking is!”

“I can’t tell you what set it off,” Deku replies, lifting his chin. “You’ll tell your Deku, and that’d ruin the surprise. It should be something he discovers on his own. But my quirk is dimension travel.”

“Ha!” Katsuki says triumphantly. “That’s a stupid fucking quirk! You can never be a hero with that!”

“You really think so?” Katsuki turns around to face him, and Deku’s visibly delighted. “You’re so wrong, Kacchan! I was one of the best heroes there ever was!”

Katsuki pauses, in the middle of pouring soy sauce onto the cooking vegetables. “Was?”

“You can see that I’m obviously not at work right now. You can say that I’m retired.”

Katsuki sticks a wooden chopstick into the noodles and stirs. “Okay. So how does your quirk work?”

“I mean...” Deku deliberates. “Do you remember how I told you about MWI? You might have to dig deep into the dark recesses of your brain.”

“Shut up,” Katsuki mumbles, embarrassed, because Deku’s making him feel stupid and he’s not. “I do.” 

“Here’s the thing—everything that I told you is wrong.”

“What?” Katsuki goes from shame to rage so fast his head spins. “Then why’d you waste my fucking time with all that bullshit?”

“Wait, wait, wait. You know how all myths are based on truth, right? A lot of what is currently modern science is just what’s observed and its interpretations. That’s just what science is. If only you let me tell you about various quantum mechanical interpretations…”

“I told you I don’t give a shit.” Katsuki carefully ladles out the noodles into two bowls and dumps the vegetables on them. He pushes a bowl over to Deku and throws two pairs of chopsticks at him, because Deku’s an asshole but common courtesy dictates for Katsuki to feed him. “I want to know how your fucking quirk works.”

 “That’s kind of difficult,” Deku says after snapping them apart, “because your science doesn’t explain much. I’ll do my best.” 

Katsuki rinses the pot and the pan in the sinks, wipes his hands with a towel. He picks up hot sauce and joins Deku at the counter. “Get on with it.”

“Okay.” Deku clicks his chopsticks as Katsuki liberally applies hot sauce to his noodles and begins to eat. “It’s easier to tell you how I interpret it rather than how it actually works. Taking MWI as truth and my quirk as dimension travel, I should be able to step sideways, if you will, into other universes. Theoretically, my counterparts and I should be the same age in every universe. It turns out that’s not true, and it actually took me some time to figure out why. How to visualize… Do you know what a loom is?”

“Yes.”

“Think of all those horizontal strings, with each string being the universe. Let’s say my universe is the furthest right string. In reality, infinite universes have infinite strings. For now, let’s say I’m at the end, so I’m the ‘original universe.’ In reality, there’s no actual thing as an ‘original,’ so we’ll use mine as the baseline.”

“According to MWI,” Katsuki clarifies, “every decision you make creates more universes and therefore more strings.”

“Yes. It makes sense that the more ‘left’ I go, and the furthest from my universe, the more, uh, warped things will get. MWI isn’t an accumulation of my decisions, it’s also everyone else’s. Going further left just means that more decisions play out differently compared to my universe.”

“We’re born at different times,” Katsuki realizes. “It’s not you moving through time but rather our parents’ decision to have us earlier, or our grandparents.”

“Or infinite other reasons,” Deku says. “Basically, yes. My quirk allows me to go from string to string—that is, traverse the universes.”

“Do the strings exist? Because Deku always says to think of the fourth dimension as linear, that the further it goes that means going forward in time—”

“The strings themselves don’t actually exist. For my intents and purposes, it’s easier for me to explain them as physical strings that I can hop to.”

“That’s an infinite number of strings. Even if you dimension hopped your whole life, you’d never get to even a small fraction of what’s out there. So…. why are you traveling?” Katsuki wonders. “Are you trying to find something to save your world? Some kind of technology? Is that how you’re a hero?” He gasps. “Do you hop into the universes that always win the battles and that’s how you win?”

Deku starts laughing so hard that he wheezes. “Kacchan, no. That’s unexpectedly clever, but guess again.”

“Hm,” Katsuki says, thrown off by the genuine laugh that looks odd and artificial on Deku’s face. “You can’t just be joyriding for the heck of it. You’re Deku—you’re always working towards a greater purpose. That takes out sightseeing. You said that you don’t do it to win. You didn’t say that you weren’t looking for something!”

“Correct!” Deku claps his hands, delighted. “But what am I looking for?”

“Tech? Weapons? Medicine? Maybe you’re dying. Are you dying?”

“No, no. I’m in perfect health, thanks for asking. But let’s say that you die, and I kill you.”

“What?” Katsuki chokes on his food. “Why are we suddenly talking about you killing me?”

“Jesus, calm down.” Deku waves his hands. “You’re so jumpy. This is hypothetical. You’re currently fine.”

“Currently?! You’re not going to fucking kill me! You’re eating my food; that’s, like, a rule! Besides, you’re too much of a wimp to kill me!”

“But if I did,” Deku continues, ignoring him, “MWI dictates that this universe will devolve into infinite others, but most of them will be defined by one where I did and one where I didn’t. This curtails rather neatly into Schrodinger.”

“I learned about Schrodinger's Cat in school,” Katsuki says, crunching on a pepper. “Anyway, you don’t have the balls to kill me.”

Deku rolls his eyes, and shovels noodles into his mouth. “So they’re actually teaching you guys something there.” He devolves in a brief bout of muttering about the various inadequacies of public education then resumes at an audible volume. “We’ve established that I’m looking for something. Let’s say that it’s a person.”

“It’s me, isn’t it?” Katsuki says, boastful. “You’re looking for me.”

“Am I?” Deku inhales another mass of noodles. He looks like a squirrel with his cheeks puffed out. “I could be looking for my mom or any of my friends.”

“Aha!” Katsuki points his chopsticks at Deku, which is bad form, but he’s got him in a lie. “You don’t have friends!”

Deku sits back, pats his stomach, and smirks. “I make tons. You aren’t my only friend. I have more. You, on the other hand...”

Katsuki scowls at the dig, scraping the last bits out of his bowl. “You’re lying. You have to be looking for me.”

He has to be. Who knows how long Deku spends in each universe. Besides, Deku was there when Katsuki came home. He definitely wouldn’t traverse the multiverse for Mitsuki—

“Wait a second, is there a multiverse? There can’t be, right? That’s impossible.”

Deku smiles, and it’s like the baring of teeth. “You’re right. And you’re wrong.”

“So…” Katsuki reads between the lines. “In essence, no one really knows what’s going on?”

“Well,” Deku says, and he hesitates for the first time. “I do. But I only did half of the calculations to figure out which universes I need to go to. Otherwise it’d just be a crapshoot.” Katsuki shoots him a look. “Hey, you think it’s just jumping from one string to another like strumming a guitar? There’s so much math and physics involved that I couldn’t even do the initial calculations alone!”

Katsuki snorts. “Yeah, right. Who helped you? Me?”

Deku stops smiling. Instead, he looks right at Katsuki, silent and intense. “Yes.” Then, like the sun bursting out of the clouds after a storm, it’s gone. “But now I can do them alone! For the most part.”

“Okay,” Katsuki says. “Let me get this straight. “You’re looking for different, uh, ‘me’s. You’ve found some. You.. did find some, right?”

“Yes?”

Katsuki still isn’t sure what Deku’s actually doing here. He thinks that if he asks, Deku will sidestep the question by going into another in-depth explanation. “So... why are you here?”

Surprisingly, Deku says simply, “I need to find the best one.”

“...Yourself in space and time?”

“No, Kacchan. You.”

Katsuki frowns. “I’m assuming your ‘calculations’ were how you knew where to find me.”

“You give me too much credit,” Deku says. “I haven’t gone far left enough that much has changed. Mainly the ages. It turns out that based on the time our parents meet is when they choose to have us. They are around the same age. Did you know that all of them met at a quirk rally? So if universes don’t have quirks—which at this spatial point is rare—or if quirks develop earlier or later, that influences when we’re born.”

“My parents met when my dad tripped over my mom’s shopping cart at Trader Joe’s.”

“Which proves my point that every universe is different. Most of the far right universes that I’ve visited are similar to mine. This is actually the first universe that I’ve jumped dramatically left.”

“Intentionally?”

“Actually, no,” Deku admits. “I messed up my calculations. I’m actually not supposed to be here. You’re too young and different and stu—you know what, nevermind. And, uh...”

Katsuki takes both of their bowls, fills them with water in the sink, and leaves them there. He’ll put them in the dishwasher later. He saunters back to the counter. “Well?”

“Well, firstly, you’re different than I remember. Although I suppose you always are.”

“Always? How many times have you done this?” Done me?

“Um,” Deku says awkwardly. He leans back his chair on two legs. “Many... times? To be fair, that’s the first time you’ve agreed to give me a blowjob on your kitchen counter! That counts as a first, right?”

“Sure,” Katsuki says, uncomfortable. “But why won’t I work for whatever you have in mind?”

Deku says simply: “You’re not good enough.”

“Hey, asshole!” Katsuki rages. “I’m totally good enough! Didn’t that stupid blowjob prove anything to you—you fucking came, right?” He smacks the counter. “Wait, why am I trying to even prove myself to you? You’re Deku. You’re useless!”

“Ouch. That’s what Deku means here?”

“What the fuck else would it mean?”

“Deku means—you know what, it doesn’t matter what it means. It changes every time!” 

“Then why am I not fucking good enough for you? Is it because I’m young?”

Deku leans forward and puts his hands on the counter. “Listen, Kacchan. Being young is not bad. I know some universes frown on having sex with minors, but I promise you that’s not it. It’s just… you don’t know enough. You’re not you enough.”

“Fuck you!” Katsuki shouts. “I’ll prove just how fucking me I can be! Just watch! Tell me what to do, asshole, and I’ll do it perfectly!”

“Okay, Kacchan. What should I watch you do?” Deku asks. “You know… you don’t even know why I’m looking for the best Kacchan.”

“That’s cause you won’t fucking tell me! You keep slipping out of everything I ask and start spouting bullshit!”

“What do normal kids do when they get home from school?”

“What does that have to do with anything?” Katsuki throws up his hands. “Hell if I know. Do I look like a normal kid to you?”

“Pot, kettle. When I was in middle school, in my free time… Gosh…” Deku puts his thumb and forefinger on his chin. “I walked on the beach, read comics on my bed, studied on the roof of the school…”

“Oh, so that’s where you run off to.”

“You can’t use this knowledge for evil.”

“Yeah, right,” Katsuki snorts.

“I’m serious.” Deku sets his chair back down onto four legs.

“Yeah, and I’m a quantum physicist.”

“In another life…” Deku trails off into silence again.

Katsuki loses his temper. “See, what does that mean? I let you stay in my home, I feed you, and all you do it make cryptic references to this ‘other’ Kacchan—”

“Other Kacchans, plural.”

“But what does that fucking mean? Okay, you’re a dimension traveler! Great! Fantastic! What are you doing here? Why haven’t you moved on? Stop being a slippery, creepy bastard and just tell me!”

Deku looks at him closely. Instead of answering his question like a normal person, he opens his mouth and says: “Jerked off.”

Katsuki jumps. “Didn’t I just say creepy?”

“When I was in middle school, I jerked off a lot,” Deku says, pleased at catching Katsuki off guard.

Katsuki sputters, completely derailed. “A virgin like you would’ve needed to jerk off or you would’ve been completely abstinent!”

“You’re a virgin.”

“Didn’t I just”—Katsuki tries not to stutter, because he needs to be chill, even though he used to be the coolest kid in school, he’s still a virgin, and goddamn, he said the same thing three minutes ago but now he has to choke it out—“suck your dick?” 

Deku’s eyes go dark with something that Katsuki’s never seen before. 

(Not that Katsuki’s overly interested in stuff like that. But he’s a teenage boy who sometimes gets desperate. He can only fist his dick so many times before it chafes. Experience taught him that he can do so many things with fingers, and when he bought lube from the convenience store, that night he came so hard that he screamed into his pillow. It’s in the second drawer of his dresser, tucked inside an empty tissue box.)

“Yeah, you did,” Deku says, getting up. “Want to do it again?”

“Not particularly,” Katsuki says. But he trails after Deku up the stairs to his room. “Will this prove that I’m the best?”

“Sure, Kacchan,” Deku says, and his mouth twists into that smile that looks wrong on his face. “I’ll keep you if you’re good enough.”

“Fuck you, I’m a delinquent! I’m not yours and I’m not good!”

 Deku actually giggles. “Do you want me to say ‘worthy’ instead?”

“Fucking fine.”

Katsuki’s room is normal. There’s some All Might paraphernalia but no other decorations on the walls. Katsuki is a very neat person, so his bed is made and all of his clothes are either in the hamper or folded neatly in the closet.

Deku whistles in appreciation. “I’ve always wanted to eat off the floor here.”

“We just ate,” Katsuki gags. “Plus, gross.”

“Eh,” Deku says casually, “once you’ve eaten ass, even the floor seems appealing.” 

Katsuki can’t even muster up any suitably scathing words to throw at Deku, who winks at him. 

“Don’t worry, it wasn’t anyone but yours.”

Katsuki, legs a little wobbly, sits down heavily on his office chair. Deku chooses to flop onto the bed, displacing the pillows.

Katsuki wants to ask him many things: how many times he’s had sex, how many times he’s fucked or been fucked. Katsuki hasn’t watched porn but he’s heard people talk enough to wonder whether Deku’s a top or bottom, submissive or dominant? Judging from the Deku that he knows, Deku’s a submissive bottom unless he grew a spine. But this Deku is different. More mature, more confident.

It feels like the lump of clay thrown on the wheel has finally been centered. Katsuki took ceramics as an elective, but he thinks that once Deku is stable, he’ll be able to shape himself into anything he’s ever wanted. He’s similar to Katsuki in the respect that he’s smart and ambitious enough to do whatever he sets his mind to. Deku is a quirkless loser, but he matches Katsuki in almost every way, even if Katsuki refuses to admit it. 

When people lose their sight, they report their other senses getting sharper. Extending that logic, because Deku lacks a quirk, that means that everything that helps him perceive quirks is stronger and more effective: namely, his brain. Katsuki’s not stupid; he’s seen Deku’s notebooks, and although flawed, they’re good. Clever, even. Katsuki can do better, but if he’s the limit, then Deku’s almost there. If Katsuki is maximum capacity, then Deku is an asymptote approaching the limit.

Katsuki shakes his head. Deku is rubbing off on him.

“You’re not the top,” Deku tells him. Katsuki stiffens, and Deku waves lazily. “Calm down. I said you’re not the top, not that you’re not the top.”

A double negative makes a positive, which means that Katsuki is… a top and not a top? He was still on the concept of limits, and he honestly doesn’t know whether Deku was referring to sex or whether Katsuki was the best.

“Honestly…” Deku pinches the space between his eyebrows. “I can hear you thinking. Which is normally sexy as hell, but seeing as we’re about to have sex, that’s not our usual foreplay.”

That’s a lot to unpack there, and Katsuki likes to keep everything neat and put away but is currently too confused to bother. Instead, he sheds his shirt and throws it in the hamper.

Deku shucks his own shirt, unbuckles his belt, unzips his pants, and kicks them off. Katsuki watches as he toys with the band of his underwear. Katsuki has a fleeting thought that Deku might be shy, until he glimpses the expression on Deku’s face, and mixed with lust is smugness.

Katsuki relaxes. He’d call it instinctual except Deku’s never elicited that reaction from him before. There’s no homicidal rage in Katsuki’s head. Instead, there’s a heat that’s steadily growing, and it crackles in the background, filling his mind with smoke. 

Deku lies down on Katsuki’s bed on his back. It’s difficult for Katsuki to think clearly, but the sole thought that resounds through Katsuki’s head is: mine.

Which is—which is stupid, right? Katsuki hates Deku. But this Deku is gorgeous, and this is a challenge. Katsuki will win this. He has to prove he’s the best.

Katsuki clumsily rises from the chair, and it clatters to the floor. He joins him on the bed, and crawls on hands and knees towards Deku’s lap. Katsuki’s ass is in the air but he doesn’t feel vulnerable. No, he’s a jungle cat; lithe and powerful.

Katsuki takes off his pants and underwear, and Deku guides Katsuki onto him. Katsuki slithers onto his body, dick dripping fluid onto his stomach and abs. He spreads his knees to the sides because Deku is wide-chested. 

Katsuki tentatively puts his hands on Deku’s chest. Deku encourages him, putting his hands over Katsuki’s and starts massaging them. “So you’re quirkless, huh?”

“Shut up,” Katsuki snaps. “I’ll still be a hero.”

“Whatever you say,” Deku says. “Do you remember talking about Schrodinger?”

“Really?” Katsuki says. “You want to talk nerdy to me right now, as I’m touching your tits?”

Deku smirks. “You could also start discussing the EDP paradox to go along with Schrodinger, but that starts to dig into Einstein and Bohr and the quantum mechanical model as well as the Uncertainty Theory.” 

“I’m only in eighth grade,” Katsuki reminds him. Deku places his hands on Katsuki’s waist and lets Katsuki touch his pecs. “There’s only so much physics that I can comprehend at once.” 

Deku chuckles. “I am throwing this all on you, aren’t I?” 

“Uh, yeah.”

“It’s okay.” Deku winds a hand in his hair and guides Katsuki down to Deku’s nipple. The other reaches in the vicinity of Katsuki’s bedside table. “I’ll go slow.”

Katsuki shudders and opens his mouth.

“The Copenhagen interpretation, the orthodox view of quantum mechanics, is an expression of the meaning of quantum mechanics that was largely devised by Niels Bohr and Werner Heisenberg in the mid 1920s.” There’s a sound in the background, like a drawer opening and objects shuffling. “It’s actually the oldest of the many proposed interpretations of quantum mechanics—and the most commonly taught in higher education, despite being centuries old.”

Katsuki laves his tongue over Deku’s nipple. Deku moves his shoulders, flexing them as if he wants to move away but is forcing himself to stay. 

But that can’t be true. Deku wants this more than Katsuki does. 

There’s a click in the background and a wet noise.

“The Copenhagen interpretation says that prior to being measured, material objects on a microscopic level don’t have definite properties.” 

Katsuki releases the nipple, licks it once, and says, “But in essence, it’s just probability.”

“Correct.” Deku guides him back down again. “There’s no logical way to take the initial conditions and figure out the future with the current model. Quantum mechanics only predicts the probability distribution of a given measurement's possible results.” 

Deku’s doing something complicated with his hand in the background; Katsuki can feel his muscles flexing. There’s no second click, and something is set on the table.

“The act of the measurement itself causes the set of probability to reduce to a single value. This is called wave function collapse. A simple example is that a particle is a wave function until it’s observed—and therefore broken.”

Katsuki bites his nipple lightly, just to see his response. 

“In regards to whether light is a particle or a wave—ah, Kacchan”—Deku bucks up, almost displacing Katsuki from his lap—“according to the Copenhagen interpretation, light is neither. Bohr’s complementarity principle states that a particular experiment can demonstrate particle or wave properties, but not simultaneously.”

Deku pulls Katsuki off, and switches him to the other one. Meanwhile, his other hand creeps around them and below. Katsuki thinks that he’s going to start jerking himself off, but Deku spreads his legs further. Katsuki thinks that Deku pushes a finger inside his own ass, but suddenly there’s a finger at the rim of his own asshole. It gently pokes and prods its way inside. Katsuki tenses and gasps.

“This puts the Schrodinger’s Cat Paradox in a new perspective, since it’s a thought experiment highlighting the consequences of accepting uncertainty at the microscopic level on macroscopic objects.”

Deku sighs, and Katsuki opens his eyes, not realizing when he closed them. Deku’s nose and cheeks are noticeably flushed. 

“Instead of devolving into two different paths, as predicted by the MWI, the description of the cat can—mm, there we go”—Deku cuts himself off, and fuck, the second finger is now inside, there are two fingers in Katsuki’s ass—“the cat can incorrectly be thought of as becoming blurred between living and dead because that implies that the cat is simultaneously both. That’s impossible because if the cat ends up surviving, it’ll only remember being alive.”

Katsuki lets go of the nipple, and surveys his damage. He tries to ignore the scissoring motion inside him. Deku’s nipples are red and inflamed. They look sore. Katsuki blows air on one, and Deku shivers.

“That’s Copenhagen,” Deku says, and maneuvers Katsuki so he’s squatting with his legs on either side of Deku’s waist, back against Deku’s folded legs. Katsuki is just about to complain that he’s getting manhandled on his own bed, but Deku pushes the third finger inside. Katsuki feels lube dribbling out of his hole. The air feels like it’s punched out of his lungs.

“I don’t care about Copenhagen,” Katsuki says. There’s not enough air. Deku has found the lube that Katsuki keeps like he knew it was there. He can’t look away from Deku’s fingers as they enter inside him, and neither can Deku.

“All interpretations are inherently flawed,” Deku says breathily, and knowing him, he’s simultaneously talking about quantum physics and something else. It’s hard to think with his brain hazy with lust. He looks at Deku fingering him open, abs flexing as he shifts to get a better angle, because he wants—he wants Deku’s fingers to touch a place inside him—

“If you wanted that, then why didn’t you say so?” Deku says. Katsuki feels his ears redden, because it’s Deku that’s supposed to be the mumbler—Deku, not him.

In fact, this entire situation is odd. Like a role reversal, but not. Katsuki shoves one of Deku’s legs further up behind him so he isn’t squatting so much as leaning back against their solidness. As he once again settles above Deku’s waist, he can’t help but feel a sense of surreal rightness. It’s deep-seating, the feeling that this is how things are supposed to be—despite Katsuki’s discomfort with sex. He keeps pushing it away, because this is normal and he’s supposed to want this.

Deku reaches over to the desk and tosses him the bottle of lube, and Katsuki catches it. “Why don’t you finish the job?”

Katsuki—ears still flaming at the fact that Deku found his lube so easily—thinks that’s odd. Deku’s fingers are longer and thicker than his, and his hole feels stretched. Katsuki feels himself make a confused face, and Deku laughs at him.

“I’m ready,” Deku says, winking, and the expression looks so odd on his freckled face, “but it looks like you want it, and only you know what feels best.”

Katsuki knows. God, he does. The bottle’s uncapped from when Deku used it. Katsuki spills lube onto his fingers and pushes two of them straight into himself. The angle is strange—he’s done it to himself, but not that often, so he kind of knows what to expect, but isn’t quite sure. He pushes his fingers past the rings of muscle—Deku lets out a low groan—and strokes his smooth walls.

Katsuki marvels at the looseness of his own ass. He puts in a third finger, then another. 

Deku props himself up on the pillow, and stares at Katsuki. He pumps his cock slowly, not enough to bring himself anywhere. Occasionally, a bead of precome forms at the tip, and he swipes it away with his thumb.

“You’re kind of a slut, Katsuki,” Deku says. 

“What?” Katsuki says. “No, you are, the fuck?”

If this was Deku Deku, the insults would come naturally, but with this one, Katsuki is off-kilter. Deku’s completely at ease and that can only come with having done it before. Katsuki’s not because he hasn’t.

He half expects Deku to get offended, but he instead laughs. “Only for you.” 

At this point, Katsuki’s hand is shaped like a beak and his wrist is cramping. For a second he thinks his thumb might accidentally go in. He’s hit by a shot of lust at the thought, and his ass almost feels loose enough for it to work. But before he can bring the thought into fruition, Deku says, “Stop.”

Katsuki stops.

Deku reaches over with the hand that isn’t on his dick and tugs Katsuki’s fingers out. He whines at the loss, and Katsuki realizes that it’s not only Deku that made the noise, but both of them.

“Would you like me to go inside?” Deku says.

Katsuki’s mouth goes dry, and he pushes down the slight nausea. “Fuck me?” he chokes out.

“Yeah,” Deku says kindly. “I’m ready for you. The question is, Kacchan, are you ready for me?”

“Yes,” Katsuki says, because he thinks he is. Even though he feels strange, he wants to do good to Deku, be good like Deku, inflict good unto Deku. He wants to be the best that he can be. Proving himself is now less of a challenge and more necessity, because Katsuki needs to measure up to the countless ones before. 

For a moment, he thinks of saying no. Instead of letting Katsuki go, Katsuki imagines Deku going ahead anyway, forcibly flipping Katsuki over and gripping his wrists, forcing his dick inside even when Katsuki yells at him to stop. Bouncing him on Deku’s cock until Katsuki tips his head back and howls—

But Katsuki says yes, so Deku smiles his megawatt smile and says, “You’re so good, Kacchan,” which Katsuki is steadily realizing that's all he wants to hear. Deku says something else, but Katsuki doesn’t hear him over the roaring in his ears.

“What?” Katsuki says, and he's barely audible.

“I said,” Deku says, muffled, and Katsuki strains to hear, “you can sit on my dick then.”

Shaking, Katsuki grips Deku’s dick in one hand and guides it into his hole. He knows it’ll fit, but he stops right before they touch. They’ll be connected with Deku linked to everything Katsuki is. They’ll ignite with the birth of twin stars and be forever glorious.

“C’mon, Kacchan,” Deku says, and he’s brave, confident. “Put it in. You’re going to be so good.”

“Tell me more,” Katsuki says.

“You’re gonna be the best there ever was.”

Katsuki feels his lips tremble. “The best?”

Deku says warmly, scorching like the sun, molten like the Earth’s core, powerful as a maturing star: “The greatest.”

Kacchan sinks down, and it’s so full and he’s so tight. He bites his bottom lip hard and breathes in deep. They press together and Deku is inside, and it’s wonderful. It’s glorious. 

Deku thrusts and builds up a rhythm until he hits that spot. Katsuki yells and everything is too much. He’s fucked himself on his fingers before, but everything is so much more present with Deku’s cock pressing big and hot inside of him.

It’s embarrassing to fall apart so soon, but the thorough prep brought him to the edge. Deku’s cock is so much more than the four fingers Katsuki has been able to take, and it’s too—he doesn’t want but he does—he’s— 

Katsuki comes with a pitiful whine. Deku groans and shivers. One hand presses on his stomach and smears Katsuki’s come on it.

Katsuki immediately panics. He’s failed. He came so fast because he was pathetic; he wanted to prove to Deku that he wasn’t useless, but in the end, Katsuki was the Deku all along. 

What if they’re the same? What if they’re the beginning and the end, two ends of the same string, and when they’re pulled together and traced to the tips, all they get is each other?

Katsuki starts to pull off when Deku smiles at him, gently, so gently, and puts his hands and Katsuki’s shoulders and presses down, keeping them together.

“It’s going to hurt now,” Deku says. “Overstimulation always does.”

Katsuki is scared because he doesn’t want it to hurt. His role is hurting Deku rather than the other way around. But in a sick and twisted turn of events, he’s grateful that Deku’s letting him do this, that Deku’s letting Katsuki stay despite Katsuki’s obvious reluctance.

Katsuki’s perfect at everything on the first try and thinks everyone should be able to do everything that he does. But that’s contradictory in itself. If Katsuki’s the best, then everyone does everything worse than him. How could it be fair to expect everyone else to get it immediately?

Deku understands, and Deku is giving him another chance.

“You can do it,” Deku says. “Kacchan is amazing and can do anything he tries. I’ve seen it with my own eyes.”

Deku starts once again to thrust into him.

Katsuki—Katsuki feels very strange. He’s never had sex before, and the penetration was good and coming was great. But even though Deku’s going slow, Katsuki’s also very oversensitive. Katsuki’s never touched himself after coming because he doesn’t see the point—he’s just oversensitive and twitchy. But now, he has no choice. For the first and only time in his life, he can’t overpower Deku.

“Please,” Katsuki says, because he failed, and now Deku will never love him most, and oh fuck, it hurts, it hurts so bad, and he doesn’t want this because he’s wrong. One of Deku’s hands goes to his cock and teases it, and it stings—“Please let me go.”

Deku smiles softly at him, and squeezes tighter, trapping him in. Katsuki digs his fingernails into Deku’s thick thighs in retaliation, and Deku doesn’t react to the pain.

Katsuki wants to cry, because it hurts so bad that he thinks he’s going to die. It feels like their connection is a conduit and there’s electricity surging through his entire body, and it’s raw and intense. Katsuki’s stuck pins in light sockets just to feel the zing, but it’s nothing like this. It feels like his body is on fire. Somehow, his face is split in an agonized smile as he grins and bears it.

“See?” Deku says. “I knew you’d love it. You always have, and you always will.”

Katsuki’s a tree in a hurricane. He has to close his eyes or get blinded by lightning. The pleasure pelts him like hail. He grimaces and suffers through it because he can do it. He has to. Deku told him that he can do it, that he’s done it before, and Katsuki needs to show him that he still can.

He bears it. It lasts about a minute total, judging by the clock on the wall, but it feels like an eternity. Mountains rise and fall by the time Katsuki’s sure he’s not going to shake apart.

He blinks and sees Deku staring at him with rapt adoration, like Katsuki is the earth or the night sky or maybe the sunset. 

“Has it stopped hurting?” Deku asks. He reaches toward Katsuki, and Katsuki is torn between biting his hand and nuzzling his palm. He’s so indecisive that Deku has already wiped the tears from his cheeks and licked them off his fingers by the time Katsuki flinches.

“One that thing never changes,” Deku says reverently, “is that you always look so pretty when you cry.” 

Deku said that Katsuki’s the first but obviously he isn’t, and Katsuki doesn’t know what to do with the fact that Deku’s done this so many times before. Deku is Katsuki’s first but Katsuki’s beginning to think that he stole it. He begins to feel angry about that—irritated and cheated—when Deku says:

“Let me fuck you now. Let me fuck you hard. You should allow other people to make you feel good. It’ll feel so nice, I promise.”

And like a doll, like a puppet, like a marionette with Deku controlling the strings, Katsuki says, “Do it.”

If Deku continuing to thrust inside after Katsuki came made Katsuki feel like he was being scorched to death, this feels like something’s igniting him back to life. Deku thrusts in and out, while Katsuki starts a rocking motion on his lap, marveling that now he can do so. He’s lasting longer, the urge to come present but in the distance, like a mountain shrouded in mist. 

The pleasure steadily consumes him, and he can’t breathe, can’t think.

“Deku,” he sobs, “D-Deku, it feels so good. Make it stop, please, please—”

It's incredible. It's inevitable. It’s so much and he’s the one being penetrated. It should be Deku who’s crying, Deku who should be squealing, Deku who should be crying hard enough that his tears drip down his face and onto the mattress. Instead it’s Katsuki who's been powerful his entire life but no longer. He competed with himself and lost, battled against a Deku who wasn’t Deku and emerged unworthy.

“You don't really want me to stop, do you?” Deku says, and he couldn’t be more wrong.

Katsuki wants, needs him to stop, because the pain turned pleasure he's receiving is entirely undeserved and therefore stolen. Thieves are cowardly; Katsuki is brave. He took a risk that didn’t pan out and now above all things, Katsuki needs Deku to let him go.

"Deku—" he says, but he's interrupted.

“Oh, Kacchan," Deku sighs, "you can't understand how much I’ve missed you. I’ve been so lonely; you know that no one understands me the same way you do.”

Katsuki doesn’t understand Deku at all. He doesn’t understand anything about everything: why Deku came, why he asked Katsuki to suck his dick, and why Katsuki did. He let Deku come to his house, eat his food. Deku directed Katsuki onto his own bed and fingered him and fucked his ass. Deku gives Katsuki so much pleasure in return that Katsuki doesn’t know what to do with it.

He thought he knew the Deku that he grew up with, but it turns out that Katsuki doesn’t know shit. Deku is smarter than Katsuki will always be, will devise situations where Katsuki thinks he’s going to succeed but ultimately doesn’t. Anyone else would laugh at Katsuki, but all of the Dekus never will. No, they’ll just chuckle, not at him but with him, and encourage him to be the best that he can and do better.

“We’re meant to be,” Deku says, eyes bright. “We always have been, and we always will. Even if I have to search for ten, fifty, a hundred, a thousand, and fucking million variations—Kacchan, I will never stop searching for you as long as I live.”

Katsuki stares at Deku’s stupid face and his stupid green eyes and is completely overwhelmed, because Deku is completely insane and he’s Katsuki’s. Deku is professing his love, and Katsuki thought he’d be completely disgusted. Katsuki’s not even horrified to realize that he’s actually enamored, because he failed, Katsuki failed, and Deku loves him anyway.

This is the way Deku shows his love. It makes Katsuki uncomfortable and awkward and scared, but the least he can do is shut up and take it.

“I adore you,” Deku continues, gasping in pleasure, “more than anything or anyone else. It’s always been you. It’s never been anyone but you. You used to hit me in middle school and I was terrified. But now I’m not scared of you anymore; no, not at all. We’re equals now, something that you said could never happen, but guess what? Here we are in the future, past, and present. It’s the two of us, together again, just like we always are and will always be.”

Katsuki tips back his head and screams, because there’s something inside him about bursting out of his chest. The pressure keeps building and building with no place for it to go. He’s losing all coherent thought, and he’s glad that Deku isn’t talking smart now because he wouldn’t be able to handle it. His body and mind and soul are oversaturated—similar to a star going nova, gone as far it can go .

“It feels so good,” Deku says, panting. He fists Katsuki’s cock as he thrusts so hard that Katsuki jerks on his cock. “Yeah, Kacchan, let me fuck you harder. Give it up for me. I’m right here. You can do it—you’ve done it so many times before, you know when it’s good. It’s just me.”

Katsuki grunts. Sweat rolls down his face and back. His hands are slick and slipping on Deku’s thighs. 

“You know how to scream,” Deku purrs. “Make me scream too, and then hear me howling. Show me what you can do. You know what I want, because you’ve wanted it all along. Give it to me.” 

Katsuki tries. He does his best. He’s never been fucked before and it’s more tiring than he expected. It doesn’t help that he’s exhausted and feeling more empty than he has in a while; he’s giving Deku all he has, and it’s taking everything from him. If Deku doesn’t let him go or tell him to stop, Katsuki is going to pour everything onto him. Deku will wring out the drops that are left and Katsuki will become a husk of what he used to be, and Deku might finally be satisfied.

As Katsuki watches Deku stroke Katsuki’s dick because Katsuki isn’t good enough to come on his own, Katsuki shudders and jerks and does his best to just come, but he can’t—

It turns out it doesn’t matter, because Deku brings both hands up to his neck and starts to squeeze. 

“Why?” Katsuki chokes.

Deku shushes him. “You weren’t enough. Just let it happen,” he says, and he’s still fucking him. “Maybe you won’t die.”

Katsuki struggles in confusion and silently screams. He’s panicking so much, but he’s tired from one orgasm and the overstimulation. He jerks against Deku and slaps at him and tries to get air in his lungs, and nothing comes. He used his last exhale to ask why a stranger was killing him.

Katsuki’s going to die. But if MWI is true and Deku is telling the truth, Katsuki’s both dead and alive. Katsuki Bakugou exists in an infinity of others that he’ll never meet or know.

Deku once said, there in the kitchen illuminated in gold by the setting sun, that Kacchan was dead. But Kacchan is just like the Schrodinger’s cat that survived: alive with no memory of being dead. Except that he hasn’t gone into the future and the atom hasn’t decayed. 

But if this isn’t Deku’s relative past, and Deku sidestepped into the dimension that Katsuki is in, that means that the event that killed the other Katsuki has already happened or must be about to happen here. The pinnacle event has resounded through every universe, compounding its resonance until the very quantum foam trembles with it.

Time is linear but it can be bent, and Katsuki doesn’t know how. Katsuki’s Deku is better at these kinds of things, has tried explaining the fifth dimension over the chessboard, Tesseracts, Kacchan, just connecting two parts of the string together, but Katsuki sneers at Deku’s queen and pretends to understand. Now he wishes that he paid more attention because the universe is unraveling too quickly for him to comprehend. 

Another Deku has taken the fabric of Katsuki, resewn it, and folded him into something new.

Katsuki can’t calculate what he’ll be in the future, but he’s currently something with a 50% chance of dying but 100% chance of being changed. Deku’s done something to him, spoken the holy language of science and offered up the right words, and Katsuki responded to the call from the void.

Katsuki can try to predict the universe, but with his insufficient understanding of anything and everything, he can’t. The flawed models—that he barely grasps the concepts—are so broken that Katsuki can poke his fingers and push his fist through the holes.

He is half of everything he is and ever will be. According to MWI, every decision that he makes devolves the universe, expanding it a trillion times in a nanosecond, like dragging scissors through a spool of thread: bursting, expanding. Katsuki can’t push the string back where it’s meant to be. It’s unraveled, spreading onwards and enveloping everything he’s ever known. Except he doesn’t truly know anything, and what little he knows he doesn’t understand. The cat’s out of the bag and Katsuki realizes that he doesn’t know who he’s supposed to be.

There’s a jerk from Deku, and it feels like he just kicks something out of view, but Katsuki is delirious and his vision is flickering. He’s looking at him from a tunnel far away. The only things he can see are the twin lanterns of green, and he can’t breathe—

Deku lets go of his neck. Katsuki gasps and chokes as the air rushes back into his lungs. He’s dizzy, so dizzy, and he doesn’t have the energy to be furious and only feels relief. Deku continues to fuck him, and the pleasure hits him like a tidal wave.

“Deku, I—” Katsuki says, hoarsely and quietly, and he’s trembling all over. He’s going to say something but doesn’t even know what, just that there is something there in his core, a certainty, that he can’t remove. It’s always been there, since he opened his eyes and saw only green. He’s so glad that Deku decided to let him go. Katsuki’s going to live.

Katsuki is going to live!

Deku pulls him down and kisses him.

“I’m close,” Katsuki rasps, because he is. He thinks, Thank you thank you thank you—

“Then come,” Deku says. “What are you waiting for, little cat? I’m right here.” 

Katsuki does. It feels like a supernova. It feels like an explosion.

Shivering through the aftershocks, Katsuki collapses on top of him. Deku wraps his arms around him and whispers nonsense into his hair, saying that Kacchan’s the best and there’s no one else like him. Katsuki knows that just like the Copenhagen and MWI interpretations are flawed, Deku’s words are nothing but lies. There’s an infinity of other Kacchans out there, and all of them are better.

He cries into Deku’s chest as Deku’s come leaks out of his ass. Deku doesn’t shush him—instead whispering, quietly, gently as to a lover, that he loves Kacchan, and Deku will always love him as long as he lives and beyond that. Their love is pure. Their love is eternal. Their love is transcendent.

Katsuki passes out in Deku’s arms and dreams of the universe: incomprehensibly massive. He chokes on the void and walks along balconies made of galaxies. He peers through windows composed of stardust, observing the creation and destruction of everything that’s ever existed and will never be.

The next morning, the bed is empty. Deku is gone.

Katsuki lies face-up on the bed and stares at the cracks in the paint. He gets up to take a piss, and stares at himself in the mirror.

There’s a ring of bruises around his neck.

Katsuki’s alive, but that means, in a universe one step to the right, there’s a Kacchan who is dead.

Deku isn’t here, but Kastuki imagines him cupping Katuki’s face with sweaty, shaky hands and asking: Kacchan. Kacchan, what’s wrong?

“Nothing,” Katsuki answers out loud. 

He wants to blink away the tears in his reflection, but everything stings just a little too much. He’s so empty that he has nothing left to give. One day, he'll be dead for real. Deku will go through with it and Katsuki won’t be enough to stop him, and his Deku will find Katsuki again through countless others. 

“Everything is just fine.” 

-

'Cause I'm telling you you're all I need

I promise you you're all I see

'Cause I'm telling you you're all I need

I'll never leave

-

Izuku’s day is normal up until the moment he finally beats Kacchan at chess. They’ve stalemated before multiple times, but today, Kacchan loses.That alone is a feat in itself, because the first rule of Katsuki Bakugou is that he never loses. He’s never lost to Deku.

But then he does, and Izuku wins.

It isn’t a simple win or an easy one—Kacchan puts up a fight, as usual. Except this time, Izuku’s struck by a sudden idea, and executes it with total disregard for his well-being.

The expression on Kacchan’s face when Izuku says, “Checkmate,” is something that Izuku will remember forever. His eyes dart across the board, obviously replaying the last few moves, and then his mouth twists downward as he checks himself again. It registers that he’s lost, and the low-burning coals in his eyes flare up to full strength.

Kacchan explodes into motion and flips the board off the table. Wooden pieces fly everyone. Izuku fumbles a few catches. Kacchan storms out without further word and slams the door behind him.

In a daze, Izuku bends down on his knees and begins retrieving the pawns and rooks on the floor. He isn’t off-kilter because of Kacchan’s reaction—standard procedure—but rather the fact that Izuku managed to win at all.

Kacchan’s key is on the ground, strung on his All Might lanyard. Izuku picks it up and puts it in his pocket.

As he slings his bag onto his back and leaves the school, he can’t help but feel a bubbling exuberance. Maybe he’s not a stupid, useless Deku after all. It’s only one win, but the first step gives an opportunity for a journey. It’s not guaranteed to be easy, but Izuku’s on his way to becoming Kacchan’s equal. For the first time that he can remember since before he and Kacchan received their matching quirk results from the doctor, he’s happy.

He skips home, shooting Kacchan’s house next door a grin, and prances into his house. Inko sees the wide smile on his face. She smiles back at him, because Izuku’s been having bad days more and more often. She’s happy that he’s happy. 

He does homework, eats an early dinner, and goes up to his room. He’s just set the lotion on his desk and opened up his computer. He’s rooting for a tissue in his pocket when he rediscovers the key.

It’s fine, though, Kacchan has a spare. Still, he should probably get it back to him. Izuku groans. Can he wait until after Izuku…? No, that’s gross. He’ll give it to him now.

He backtracks his way to the kitchen, briefly explains to Inko what he’s doing, and heads over to Kacchan’s house next door. He knocks on Kacchan’s front door, and it swings open under his touch.

That’s a little weird, but no cause for alarm.

“Kacchan?” Izuku calls out. There’s no answer. He pushes the door open and walks inside. He’ll leave it on Kacchan’s counter so he can see it when he comes downstairs, and pauses as a sensation runs down his back. 

It’s like someone walked over his grave. There are shivers up and down his back. His hands go numb, and he’s struck with the sudden urge to…

There are noises from upstairs. A sort of scuffle. Izuku runs up the stairs and to Kacchan’s room until he’s in front of his bedroom door. Maybe he’s in trouble! It’s open slightly, and that gives him a direct line of sight into Kacchan’s bedroom.

He stands and stares.

He can’t comprehend what he’s seeing. He breaks it apart into small manageable pieces.

There’s a bed. Kacchan is on it. Kacchan is there with another person. That person is an adult man. Kacchan is straddling his waist. The man is naked.

Kacchan is naked.

Izuku swallows. Kacchan is gorgeous. 

Kacchan is having sex, and Izuku is watching Kacchan fuck another man on his bed.

Izuku… doesn’t know what to think about that. So many feelings are passing over him that he can’t quite process what they are. He feels hot and cold at the same time, filled with an exuberant happiness but also with an all-consuming rage. There’s lust too, familiar as his own right hand, and Izuku’s straining against his underwear.

But the jealousy. That’s new.

Izuku’s always known Kacchan as his. That is the way things have always been. Kacchan is mean to him now because even though they don't have quirks, Kacchan is so much stronger. That’s okay. Izuku will find or steal a quirk—whatever it takes—and then he’ll be able to stand on the same stage as Kacchan. 

Izuku might be smart and clever and good at school, but he’s missing one essential part of himself and that is a quirk. It’s a lack of something he doesn’t want but rather needs. The lack of a quirk makes him deformed. It automatically makes him inferior, and that’s a sin.

Izuku can’t tear himself away from the carnal scene in front of him. Kacchan’s eyes are closed and his mouth is gaped open in pleasure. Izuku can’t recognize the other man’s face but for some reason it’s familiar... But in that second, he wants to burst into Kacchan’s room and strangle that man alive.

The man is talking, because Kacchan is showing reactions to everything he says, but Izuku can’t hear anything he says over the pounding in his ears. Kacchan’s responding as well, and there’s white noise covering everything.  

Izuku’s hand is in his pants, and he doesn’t know when or how. He pushes the foreskin back on his dick and mindlessly starts to jerk himself off.

Kacchan looks like he’s almost in pain. His shoulders shake, and as his face scrunches, Izuku realizes that Kacchan is crying.

Kacchan is crying. Big, heaving sobs wrack his body as he tries to pull away from the man. Izuku watches in horror as the man wraps his legs around Kacchan and makes him stay.

Should he go…? Should he intervene? Because the man is talking kindly to Kacchan. Why is Izuku hesitating?  

He whips his hand off his goddamn dick and bursts into the room, but before he can do anything, the man looks straight at him, shakes his head, and puts a finger to his lips.

“Just watch,” the man mouths silently, and Izuku knows how to read lips but he wishes that he didn’t. “I’m not doing anything he doesn’t like.”

Kacchan moans. Izuku thinks that Kacchan isn’t processing anything that’s happening, only the sensations of getting ra—fucked.

The man begins to thrust into Kacchan again and Kacchan lets him. Just a few strokes, and Kacchan tips back his head and starts yelling.

“Oh, god,” Izuku says quietly. Everything is screaming for him to move, but his feet stay rooted to the floor.

Eventually, the shouting peters off. Kacchan continues to sob, looking like he wants to get away, but the man’s hand comes to his face and caresses it. 

Izuku watches in horror as the man brings his hands to Kacchan’s neck. They twitch, looking like they want to squeeze. Izuku’s breath catches in his throat, but the man lets go.

Then, something strange happens. The man lifts one hand, closes his fist except the pointer finger, and directs it to the door. 

He’s pointing at Izuku.

Two words suddenly appear in his mind, resounding like a bell. They echo off the corners of his mind and sink into the fabric of his being. Illogically, impossibly: you’re next.

Izuku stares uncomprehendingly, but the hand is brought back down, Kacchan none the wiser.

Kacchan is busy mindlessly repeating one word, over and over again. It has two syllables—two just like the words you’re next, two like a binary system, two like Deku and Kacchan— and Kacchan yells them with such a delicious variety of expressions on his face. Izuku stares and stares, and he can’t tell whose fucking name Kacchan is yelling until somehow, against all odds, a single shriek breaks through the barrier and comes muffled to Izuku’s ears.

“Deku!”

That—that man, that must be him. But Izuku is himself and only himself, which means that either Katsuki is fucking strange men and pretending they’re Izuku, or—

That man is actually Deku.

Which actually… isn’t that surprising, and Izuku’s mind whizzes. That assumption leads to two conclusions: time travel or dimension-hopping. Well, three; the third being insanity, and Izuku’s not senile yet. 

The first two mean quirks. He wonders how exactly Deku came to be here. If it was a quirk, that means that it’s most likely his. Dormant quirks are rare, but possible. Under what conditions would his quirk activate? 

Something good, hopefully. Probably something bad.

Izuku numbly watches Deku fucking Katsuki, and then Deku brings his hands up to Katsuki’s neck and squeezes. And unlike the first time, this is for real. Katsuki jerks and gags. 

Izuku’s feet finally unstick and he runs forward without processing, because he needs to get Kacchan out of there. He’s thrown back by Deku kicking Izuku straight in the chest, and it’s like being pummeled by a horse. Izuku flies backward, the wind is knocked out of him, and lands on the floor. His body throbs and aches. He can only stare in horror as Kacchan is literally being fucked to death.

“Please,” Izuku croaks. He tries to get up, but he can’t. “Please don’t do this.” 

And… Deku stops. Just lets go of Kacchan’s neck, tells him to come, and Kacchan does. Just like that. Then Kacchan passes out.

Izuku blinks hard, and comes back to himself. His dick is limp, and his underwear is soaked. He just came while watching Kacchan get strangled. Bile rises in his throat.

Deku pulls out of Kacchan and lays him on the bed. He gets up and walks over to where Izuku lays on the floor.

“He hates suffocation the most,” Deku says, and prods Izuku with his foot, and Izuku groans in pain.

“I would've killed you if you murdered him,” Izuku says quietly.

“Then in another universe, we’d both be dead.”

Izuku puts it together fairly quickly. “MWI?”

“MWI.”

“...Goddamn it. And fuck you for hurting Kacchan.”

“I did you a favor,” Deku says. “The Deku that’s one step to the right didn’t.” He reaches out a hand to help Izuku up. Izuku considers not taking it, but he’s having considerable trouble getting up on his own.

“Isn’t that fatalist?” Izuku says, letting Deku haul him to his feet. Izuku tries to hobble over to Kacchan, but Deku blocks him with his hand and Izuku aches too much to physically push past him, although he tries. “Doesn’t that mean that your choices don’t matter, because in another universe they’ll come to pass? Does that mean you have no sense of agency? Why are you doing this?”

“I need to find Kacchan,” Deku says. He puts one hand on Izuku’s chest and shoves him backward and away from Kacchan. “Mine is dead.”

Quirks only activate under specific circumstances. Deku needs to leave and he tried to strangle Kacchan. This means that either a death activates his quirk, or Kacchan does. But the fact that Deku’s Kacchan is dead is suspicious. If it was someone else who killed him, Deku would’ve said so. Since Deku tried to kill Izuku’s Kacchan and Deku’s Kacchan is dead, there is no other purpose in a murder except the reason that brought Deku here, then it stands to reason that—

“You killed him,” Izuku realizes. “You killed your Kacchan to activate your quirk.”

“It was an accident,” Deku says. “I didn’t mean to. We were supposed to do this together. Traverse the universe side by side. But I…. I got lost.”

“That doesn’t make sense. If you had to kill Kacchan to activate your quirk, then you wouldn’t have known that you had one in the first place. So you and Kacchan couldn’t have planned to travel together. Why are you lying?”

“One step to the left,” Deku says. “Just one step to the left, and we could’ve been together forever. But I miscalculated and now I can’t find my way home and no Kacchan can help me.”

“I don’t care about that,” Izuku says, and tries once again to sidestep Deku to get to Kacchan. Deku easily blocks him, and Izuku grips his hands in his hand, frustrated. “Why did you do this to my Kacchan?”

“Deku,” Deku tells Izuku, “you have to realize that first and foremost, fucking with Kacchan is really fun. I figured I’d get to fuck your Kacchan for a little before I went. It’s not like it matters. He’s not the right one. He can’t be.”

“I assumed you manipulated him with ‘being the best’ or some variation of that. I bet Kacchan rose to the challenge because you challenged his ego.”

“He wouldn’t have gone along with the sex if he didn’t have the mindset of him proving to be the best. Such are the consequences of obvious personality traits.”

“You’re a manipulative bastard.”

“I admit it.” Deku spreads his hands. “And I was supposed to kill him. He’s not mine. Although I didn’t think so at first, almost every Kacchan disposable. Infinity is just a concept, but I’ve seen it and I can tell you that for every Kacchan I kill, there’s an equal amount or more that live. He’s not my Kacchan, he’s yours. And you’re so far to the left that why should it matter to me who lives and dies? That’s how it is, and that’s how it’ll always be. But for some godforsaken reason, I’m the Deku that doesn’t kill your Kacchan in this universe. Luckily, I’m not stuck here because I have a few jumps left, but”—he sighs irritatedly—“it’s a lot harder. Whatever.”

“You didn’t kill Kacchan because you chose to do it.”

“Wrong. Do you honestly think I’d choose to get put on this string?” 

“String? What does your quirk look like when you use it?”

“I explained it to Kacchan to imagine every universe as a string of a loom. But to you, it’ll make a bit more sense if I just say it literally looks like Kacchan’s pool.”

“Oh my god,” Izuku says, and laughs despite the numbness and horror that he feels. “Really?”

“I’m not kidding,” Deku says. 

“How does that even work?”

“Math.”

“Of course.” Izuku tries once more to stumble towards Kacchan and Deku shoves him away, hard. Izuku hisses. “And I’m guessing that I’m supposed to figure that out myself.”

“Kacchan helps you,” Deku tells him. “But not your Kacchan. When you jump for the first time, you take one step to the left. That’s the Kacchan that’s closest to yours, because that’s the Kacchan you choose not to kill.”

“What about the Deku already there?”

“He can share,” Deku says. His eyes harden, and for the first time, green lightning sparks around him. “I don’t like sharing.”

Which means that this Deku must’ve killed other Dekus as well, for no reason other than to have a Kacchan that isn’t his all to himself. If Deku doesn’t care about Izuku’s Kacchan, then he doesn’t care about Izuku either.

“Will you kill me?” Izuku says. He doesn’t want to die, but if Deku chooses, then Izuku will. Not because he believes Deku’s garbage about inevitability, but because Deku is so strong and right now Izuku is weak.

“No. I don’t have a reason to.” Deku takes a breath, and Izuku lets his out. “All I want to do is find Kacchan.”

“Then why are you here?” Izuku says, and he’s shaking with frustration. “This isn’t even close to your universe.”

“I can’t find my way home,” Deku says. “I messed up the calculations, and every time I jump, I’m further left than I was before. But I’ll make it. I promised him.”

“How?”

“I’ll follow him,” Deku says, and puts his hands on Izuku’s shoulder and Izuku is too afraid to shake them off. Deku’s eyes bore into his until it’s all Izuku sees. “I’ll follow the trail of Kacchan until I die.”

Izuku hates Deku with every fiber of his being. He doesn’t believe a single word that Deku says except this. Izuku knows for a fact that if Kacchan was in danger, Izuku would carve a path to him even if it destroyed everything he is. 

What’s scary is that he can sympathize with this Deku, just the tiniest bit. It makes him nervous because he’s not Deku. He’s not.

One niggling fear permeates his mind: what if he pushes back against Deku and becomes like him to protect Kacchan, that’s the way Izuku kills him?

“I’ll never forgive you for trying to kill him,” Izuku tells him, wrenching himself away from Deku. “I’d try to kill you now, but I’m still weak. But I’ll never forgive you for toying with him and hurting him.”

“That’s okay,” Deku says. “You’ll never forgive yourself for every Kacchan that you kill.” Izuku flinches. “But it gets easier. The pain converges.”

“I will never kill Kacchan,” Izuku says. “I won’t, even if that means I remain quirkless.”

“Listen to me, Deku, and listen to me closely,” Deku says. “You talk big now. That’s okay. You’re young and idealistic and in love. But what you don’t realize is that you’ll kill him either by accident or on purpose. Regardless of whether you met me, your path is set. You’ll be forever obsessed with your quirk and Kacchan, and eventually you’ll snap. Because you can just find your Kacchan the next universe over, and that Kacchan will never remember you killed him.”

“I won’t!” Izuku shouts, tears in his eyes. “Stop talking! Just because you have a sob story doesn’t make you right or excuse your actions. So your Kacchan died. It’s sad, okay? I get that it’s devastating. But why do you need to go around killing other Kacchans? What is the point?”

“Oh, Deku,” Deku says. “Did you really think you only needed to kill one Kacchan to jump?”

“You said that killing Kacchan activates your quirk!”

“You seriously think it’s that easy? That one death will fuel your jumping?”

“Yes,” Izuku says, and dread is building hot and thick in his stomach.

“Depending on the distance you jump, that determines whether you need to kill Kacchan,” Deku says. “And if you jump enough small distances, you’ll need to do it anyway.”

“What? How many Kacchans have you killed?”

“I…” Deku scratches the back of his head. For the first time, he looks ashamed. “I don’t remember.”

“You don’t remember?”

“Why’d you try to jump in and save him?” Deku asks him sharply.

“W-why? Because I couldn’t just stand there and watch him die,” Izuku says, trembling with anger. “You of all people should understand. He’s mine.”

“He’s been nothing but a brat to you your entire life. He hurts you and you don’t even bother to hit back. He’s so far to the left that he’s not even a semblance of who he’s supposed to be. He doesn’t even have a quirk,” Deku sneers. “No matter what you say or what he’ll do, neither of you will ever measure up. You’re just the products of bad choices someone else made. This universe is worthless, just like all the others. The only purpose that it serves is a stepping stone. And you know what? I didn’t get what I needed anyway. This one isn’t even worth the trouble.”

Something inside Izuku snaps.

“Get out of the house!” Izuku screams. “Get away from him. Get away from me!” He rushes at Deku to beat at him uselessly with his fists. “Go away! Go away!”

“Okay,” Deku says. He looks to the left, to the direction of… Kacchan’s pool in his backyard. “Just remember, Deku. The more left you go, the further and more different everything becomes from what it was before. Whatever you do, you can’t run from yourself. No matter where you go or what you do, you’re inevitably going to end up the same way. You will kill him.”

“I won’t!” Izuku yells. His hands are shaking and he feels like the world is closing in around him. “I’m the one who determines my future! I’ll be the Deku who doesn’t kill! I’ll be the Deku who saves him instead! Now shut the hell up and go away!”

Deku sighs, and all the anger and the malice suddenly drain out of him, and what’s left is something deflated and bone-tired and lost. “If you say so,” he says. “Hold onto your resolve then, Deku. I don’t believe you can choose what happens next, but you really believe it. In a way, it’s almost better for you because you think you have control. I’m looking forward to when you realize that we’re both the same all along, but I’m broken now and I really fucking wish I could’ve stayed the way I used to be. But we have to grow up at some point, Deku. Even you.”

Deku closes his eyes and disappears. Izuku stares at the space where Deku used to be.

He thinks that maybe he should feel sad for Deku. He lost his Kacchan and went crazy. Maybe because he lost that one thing that defined him, that made him lose all sense of self. But Deku is wrong. Izuku is not naive. He has control. He won’t let himself turn into the Deku he saw.

Izuku finally makes his way to Kacchan, limping step by step to the bed. Everything hurts. He checks Kacchan’s pulse as best as he can. It beats strongly against his fingertips. Izuku sighs in relief.

“That won’t be me,” Izuku says over Kacchan’s unconscious body and stares at the marks and bruises that Deku inflicted, blooming like watercolors on Kacchan’s skin. “It won’t. I won’t let it. I believe that I have control over my own destiny. MWI states that anything can happen, but I can’t believe that I’m thrust into universes without me choosing what I’m going to do next. That stands against everything I am and who I want to be. I have agency. I have will.

“I know you think that you ruined my life, but you didn’t. You just showed me one of the ways it can go wrong. You broke Kacchan because you think he’s just one of countless others. You may think that he’s disposable and meant to be broken but I disagree. I think Kacchan is strong enough to always put himself back together. If he’s not, then I’ll be there to help.

“You think you’re broken, and maybe you are. But that doesn’t excuse that you just ruined Kacchan’s life and now I have to clean up the mess you made.

“But I’m not broken, Deku. I can’t be. Kacchan needs me. If I’m broken, that means I’m going to end up like you. I don’t want to kill Kacchan. I don’t want to be the reason that he dies. I don’t want his death to turn me into the monster that you are.

“So I don’t believe you, Deku,” Izuku Midoriya says to no one at all. “I can’t.”

 Izuku stares at Kacchan passed out alone on his bed, naked and covered in come.

Maybe Izuku sticks around because Katsuki is Kacchan and Izuku is a moth flickering to the flames and just can’t look away. Izuku gets burned and maybe one day his wings will be torched off, but it has to be worth it, right? Because Katsuki is Kacchan and Izuku is Deku, and there is no other way to be. This is how it’s always been. This is all he’s ever known.

This is how he’ll always be.

Izuku looks at Kacchan’s body, small and bruised and alone. Izuku smiles so wide it hurts even if all he wants to do is scream, because Deku has ruined his Kacchan. He’s fucked Kacchan into pieces and put him back together into someone else. He broke Kacchan just for the sake of ruining something that’s Izuku’s. Izuku trembles with rage and throughout all of that, he smiles.

He smiles because he knows one thing, and that is he’s going to take Kacchan, protect him, and make him his and only his, always and forever. No one will be able to hurt him ever again. And for that, he’ll do anything.

Absolutely anything.