Reinhardt was preparing to enter the building and eliminate the threat, but the building itself was completely unaffected by any magic or attacks, so the only entrance was through the door in front. He brought the entirety of the forces of Lugnica after the amount of power he sensed from the pillar of light.
Meanwhile, in the chamber, everyone was getting accustomed to increased gravity, and the gravity was increased to 4x, Meili was in a room that was separate from the training area, in which the gravity was lower, at 2x. The force of gravity on Gogeta was equal to that of a black hole. As a result of the immense gravity, Gogeta actually managed to reach beerus's level of power while only needing to power up into Super Saiyan.
"Aw man, there isn't anyone strong enough for me to fight..." Gogeta whined comically.
"Couldn't you just suppress your power and try fighting me?" Subaru questioned.
"What I want is a fight where I can go all out, Suby, I just can't really find that here."
Then Gogeta sensed some more power signatures, he looked over to see Reinhardt and several hundred knights with him. "Are you falling to the dark side now? Why is she here?" Reinhardt questioned looking over at Meili, who cowered.
Because of reasons for plot convenience, Subaru had replayed his memories against Elsa and how he threatened Meili.
Reinhardt didn't understand, how could a kid like Subaru attain such a level of power, the kind to destroy every last cell of Elsa, and then, how did it cause him to become such a violent warrior? His desire to take Subaru into custody grew, Gogeta picked up on this, and walked in Reinhardt's direction, going Super Saiyan.
"I know what you're trying to do, I'm not letting you take Subaru away," Gogeta said calmly as he walked over to Reinhardt. Rem was going to try and stop him, but Ram assured her, that he would be fine.
The knights assembled in front of Gogeta and surrounded him, Gogeta simply walked through them, not even struggling in the slightest. Then he suddenly had a realization and snapped his fingers, and the global gravity increased 10x. All of the knights, including Reinhardt, were instantly pinned to the ground, unable to pull themselves up.
"What did you do?!"
"I just increased the gravity to 10x that of earth, the gravity all of us besides that girl train in," Gogeta replied smugly whilst doing single-handed, handstand push-ups in front of him, shocking Reinhardt. Gogeta then comically slapped, kicked, and punched all of the knights out of the chamber, and then Reinhardt remained. "Alright, you can leave on your own, or I can kick you out, either is fine by me."
"Not until I make sure the power I saw is suppressed!" Reinhardt saw Subaru as a genuine threat, which he was, but not to the kingdom, which Gogeta then explained, "He just gets thrown into a rage whenever that transformation occurs, and it seems to increase his power hundredfold, so it's safe to say, you'll have a hard time if you try to fight him. But he doesn't have anything against that city, so he won't attack it."
Reinhardt let out a sigh of relief, and then was flicked out of the time chamber, tumbling 40 feet away from the door. "Ouch."
"I was getting tired of having you take up space in here, we need to get back to training, isn't that right everyo- hey, where's Roswaal?"
"He became bored of watching this and retreated to the mansion I presume." Rem held a finger to the side of her head.
"Hopefully he doesn't try turning on us." Gogeta thought to himself, a hand on his chin. He hadn't tried learning how to use magic because it hadn't been nessecary, but now he sees that all it would take is one spell for them to turn his own energy against him, and cause the destruction of the entire universe. The enemy would die, but then so would everything else in the universe, which isn't exactly ideal, unless Gogeta were evil, which he isn't. So his goal now is creating a field around him that takes incoming magical attacks and removes any spell they have. Gogeta would still be impacted by magic that was purely offensive, but he is essentially indestructible, so those are unlikely to pose a threat, or at least for the moment.
"Hey Emilia, think you can help me create a barrier that negates the effects of magic?" Gogeta waved to her. To which she nodded and they began experimenting. And gogeta failed a mere 30 times before obtaining a shield that somewhat worked. It could deactivate an attack's magical properties, but Gogeta would need to manually focus his energy on the spell. Not great, but still could prove vital.
-back in the Mansion
Gogeta is busy sorting out food at the request of Rem and Ram and is doing it so quickly, that he created a wind current that forced Ram and Rem to hold their skirts down.
"Gogeta, slow down!" Rem exclaimed, eyes shut because of the wind.
"Huh?" Gogeta stopped and looked in their direction and saw them holding their skirts down, and he instantly understood the issue.
"Oh, hehe, sorry!" Gogeta made his best Goku impression, which Rem thought was adorable, although she hid the fact she thought that.
"Good grief, you brought out everything in just a mere minute..." Ram wasn't sure if she should be surprised or not.
"Alright, time to cut the grass!" Gogeta sped off again, this time though, he made a wall of ki to block the wind. This helped avoid another embarrassing situation.
Subaru meanwhile decided to go and tease Beatrice a bit. It had been several years (Time chamber compression) that he had seen her.
"Hi, Betty!"
"How many times must I tell you to stop calling me betty you sl-ouch!" Beatrice went to punch Subaru, but hurt her hand instead. Then she realized the amount of mana Subaru had coursing through him, it was less than the maids, but it was still very high. "Hmph, I suppose that you had a change of mind and became serious, so I'll convince myself to endure your presence for now."
"I've been complimented? Is this what divine reward feels like?" Subaru put a hand to his chest and lifted the other into the sky.
"You may be stronger but you're still the same hopeless idiot you were upon arriving."
"Doh!" Subaru crumbled to the ground, fake tears streaming down his face, "You're so cold..."