Oh, I Catastrophize (MHA)

Izuku shows who's boss

Aizawa had heard a bang from the area where Izuku's test was being held. The support department. Of course. 

He sighed. What had the vigilante done this time? Probably something bad. 

All the teachers had heard the loud noise.  They walked towards the workshop together, discussing possible reasons for what it was. 

"Maybe Power Loader got fed up. I know I wouldn't be able to stick that kid's sarcasm for long," Vlad said, watching for the others reactions around him. 

Aizawa rolled his eyes. "Vlad, the vigilante may be sarcastic, but he has seen a lot more things than some heroes see in their lifetime. He's not bad at all."

"Yeah, he can't be too bad if Shouta has taken a liking to him. And one who has baet Eraserhead in a fight no less."Present Mic's laughter filled the hallway, most of the other teachers laughing along with him.

"The kid doesn't like me for some reason. I can't figure out why. Any people I've met before have immediately liked me, not that I'm bragging. I'm just confused," All Might said, contemplating the reasons why the boy was so hostile towards him.

"One thing I know about Loki is that everything he does has a reason. I'm sure you all will find out when he trusts you. I encourage you to build a good relationship with him. He will be here for as long as possible. He knows his stuff well." Nezu's words shut them all up, the thinly veiled threat hidden behind the cheerful smile plastered on his face.

They arrived at the support testing area, the door creaking loudly when the shoved it open, laying their eyes on the chaos within.

Smoke flooded the room, the open windows helping to clean it out of the room. Power Loader was at the opposite wall, groaning quietly from the force of whatever had been in the room. In the middle stood Izuku, a small contraption held in his hands along with a small layered thing.

"What the hell happened in here." Midnight's voice filled the room, disapproving glare thrown Loki's way.

Aizawa watched Izuku fit the layered object on top of his contraption, and then slot a small lighter in the gadget. It fit together perfectly, leaving him smiling happily at it.

"Oh yeah, there was a minor explosion. Don't worry, everything's fine," Izuku explained simply as if expecting them to not be shocked.

"If that's what you call minor, what's a big one?" Power Loader groaned out, lifting himself from the floor using the wall.

"Well, there's been a few before worse than that one. A few of my scars are from testing out my gadgets." 

Aizawa heart may have skipped a beat at being reminded of the kid's scars. A patchwork of red skin, and white lines criss crossing across his body. He hadn't really noticed it when they had been treating him for his injury on his abdomen, but now he could remember them. 

"Anywho, Power Loader, I'm done!"

"Good job Loki, what did you make?"

Izuku's smile widened significantly as he brandished his new weapon.

"This is a flamethrower with a twist. So it has a small container of gunpowder, which can be refilled, but also only shoots out a certain amount, which can be decided by the buttons on the side. There is a small, medium, and killer blast. The lighter sparks the gunpowder inside the metal, which is why the metal is heat resistant and won't melt unless under extreme duress and heat. The twist is that it has another container, that automatically sucks up other substances which it can identify as acidic. This will usually work best for a gas, but can be applied to a liquid if it is touching it. It will assess if the substance should be heated to become more powerful, or if it should dispense it normally. Midnight's quirk actually inspired me to make this. I tested on a sample of her quirk I collected a few months ago and found that if you heated the gas, it had more promising effects on women, as it already has very prominent effects on men. It increases the effect on both sexes, and if you heat it enough, it can actually become poisonous. It's very cool."