Seeing the newcomers, Muzan growled in anger and couldn't believe that someone like Asta can still find their dimensional fortress. The leader of the demons saw a glimpse of Asta's devil smiling and waving at him.
'Hello there, motherfucker.' Leon chuckled in his aura.
'That devil...He must be the one who sent those pests in here!' Muzan thought.
"How could this happen?! How did you enter this place?!" Muzan angrily asked.
"Hey! It's your fortress' fault on why we entered in here!" Zora said.
"I won't let you hurt Asta or any of my friends in here!" Gordon said.
"Boy, can I switch myself to yours right now? Let me explain some things to this clown." Leon said
'Sure.' Asta thought. The devil-possessed kid now smiled and his the sclera in his eyes turned black and his lens changed into red ones.
"Hey, Muzan! Do you remember this voice, aren't ya? Listen, the reason why we got in here is that you really suck at concealing the fortress! As we came out of the estate, we only saw nothing but no one and the dust swirling around the road. And I noticed something strange about it.
I asked some runts to come with me and inspect the dust that continued swirling into the road and I found out that it is the air pressure that your fortress blows so that it can float like a spaceship, which is a really cheap way of concealing it to everyone. Only with demonic powers can enter the fortress and as I ask this body to slash his sword into the dust, I saw a crack into it and opening it, was you guys fighting some random people and our fellow Demon Slayers like Tanjiro.
So, you can't hide yourselves now because we are going to crush you!" Leon said and now Asta takes back his body over.
'Nakime forgot to run this place away from the estate. Wait, if I can still use her right now, she can fix those leaks right now.' Muzan thought.
"Naki--" Muzan was stopped as Gyaku imprisons Nakime in his time sphere and all of the demons in the fortress got burned by Gordon's poison magic.
"How could you." Muzan uttered.
"Muzan!! I'll fucking slash your head into pieces!!" Sanemi roared.
"Let's cooperate as one and defeat this monster for good!" Shinobu said.
"I won't let you go away this time, Muzan..." Iguro coldly thought.
"Tch! I think this is going to be me against the Demon Slayers and some random brat who has a devil with him! Then, take this!" Muzan roared as countless tentacles with poisoned blades on the tip of it now rushed the Demon Slayers. The newcomers dodged the blades and Asta flew to where Zenitsu is.
'He turned into a demon?!' Asta thought.
"Smack him with your sword, boy!" Leon ordered. Asta rushed into Zenitsu who has his sword stabbed on All Might. The Thunder Breathing user jumped away and charges his ability in the ceiling.
"Hell Lion's Breathing, Sixth Form, Penalty Swing!" Asta swirls his whole body and flashes in front of Zenitsu, he slashes his sword on his neck and this made him back to normal, but blood spurted out from his neck.
"Gah!" Zenitsu cried as he returns to normal but receives a huge wound from Asta.
'You may turn them back to normal, but that doesn't guarantee that they are safe from my curse. As you try removing the curse from them with a weapon, their skin will be so thin that even a pinch from a human can wound them.' Muzan thought with a smirk. Gyaku appeared in front of Zenitsu and a clock appeared on his palms, which makes Zenitsu's wound heal.
'What?!' Muzan thought.
"I reversed the time to heal your wounds. Can you stand up?" Gyaku asked while offering his hand to Źenitsu.
"Y-Yeah. But hey! I accidentally stabbed All Might! What have I done?!" Zenitsu cried.
"Don't worry. He understands that you didn't mean that one. You were actually controlled by Muzan by the blood he injected into your body. And that's why you started to act crazy like a demon." Gyaku said.
"Asta! Take care of Bakugo over there! That monster looking exploding bastard!" Zenitsu yelled.
"Where?" Asta asked as Katsuki kicks him from above and they crashed on the ground.
"Asta!" Nero yelled. Katsuki grabs Asta's head and blasted it with his palms filled with an explosion. But the explosion Quirk user didn't notice that Asta's head is too hard for his explosions.
"It hurts... you know." Asta uttered. He chokes Katsuki, lifts him, and slams his body on the floor, powerful enough to crack the whole fortress. Asta's right hand released some black mist into it and rushed into Katsuki's body to remove the curse.
"This is good, I think." Asta said. He didn't notice that Izuku can be seen from above flying downwards as he prepares his fist for a huge punch.
"Detroit..." Izuku uttered.
"Wait! He has returned to normal!" Asta yelled.
"SMASH!!!" Izuku roared as he punches Katsuki into the gut and a huge amount of blood splattered into his face. Some of Muzan's cells crawled away from Katsuki but Asta fires a black flame into it.
"Wait, how did I do that?!" Asta asked in shock.
"I'll tell you the details later. For now, let's focus ourselves on this man." Leon said. Muzan can be seen being swarmed by the slashes of the Hashira's blades and All Might lies down on the ground, getting assisted by Kirishima, Sato, and Tokoyami.
"Midoriya went too far against Bakugo! I think he is dead by now!" Denki yelled.
"From my point of view, Midoriya really mushed that attack to Bakugo due to the anger he's feeling. He sees All Might stabbed, Aizawa sensei now dead, and all of us at the disadvantage. Maybe right now, he'll get back to himself once he sees his surroundings." Shoji said. Izuku sees his hand planted on Katsuki's chest as he sees it all broken and crushed.
"I... I... I crushed Kacchan's body... And my hand is... broken." Izuku said. But his injury quickly returned to normal as Gyaku assists them.
"Oh, so you're Izuku Midoriya, the last member of the Death Three?" Gyaku asked.
"D-Death Three?" Izuku uttered. Muzan continued his rampage against the Hashiras who can't even land a single blow on him. Nero, Zora, and Gordon can be seen firing their magic on Muzan.
"Magic? Like hell, I can be easily hit with those!" Muzan roared as a slimy beast appeared underground and receives the magic by blocking it.
"Huh?!" The three shrieked.
'This thing should be good enough to withstand their magic. But the real problem here is that guy, who heals those pests.' Muzan thought. He didn't notice that a stab from a Hashira can be seen and it is known to be Giyu who surprisingly appeared below him.
"You!" Muzan growled.
"Tomioka!" Shinobu yelled.
'If we can't defeat you with this kind of strategy, I'll do it by myself!' Giyu thought. He drags his blade around Muzan's body and makes an S looking wound on his body.
