MHA Story And Quirk Ideas

Quirk: Hacker

Izuku's quirk is Hacker. It's an emitter type that lets Izuku hack into anything, so long as there is viable "coding". As a sub-ability, he can also enter the places he hacks into as a pixelated version of himself. If he enters a person he takes over their body like a computer virus, and once he leaves there is always a backdoor of sorts left there for easy access. If you try to trace his hacking, you are always met with a dead end that says "Nice Try" before shorting out the person's device due to Izuku's Quirk's natural protections.

"Coding" is a loose term. It really means anything with a semblance of coding or programming. That means Biological Weapons [Nomu], actual technology, and certain people [Those with tech-based quirks like Ida].

One of the things Izuku can do is Edit. This is especially painful and unethical to use on people. When used on tech it allows him to edit how it works any way he wishes within reason. On people it let's him edit how they look, their genetics, pretty much everything. As such, when he hacked the USJ Nomu he edited it to look more Hero-Friendly, with Izuku's hero logo branded on its back. Since Izuku's real body is very weak and frail due to the limits of his quirk, he calls it his Battle Body and he uses it to fight while Izuku's real body stays back and far away from the fight.

Izuku summons a floating keyboard and screen that he uses to hack things. He can also toggle if it's visible to other people.

Downsides

Izuku's quirk sacrifices muscle for smarts. The more he works out the smarter he becomes tech-wise [And only tech-wise], however it caps his body at "Slightly Defined" as compensation.

Izuku's body will be helpless when he's possessing someone else. It still functions normally and he appears to only be knocked out, as well as functioning similarly to being unconscious.

People will subconsciously fight to keep control of their bodies. The more aware they become of Izuku trying to get in the harder they fight it. Once Izuku get in though, its permanent. He can come and go as he pleases without a fight. Mentally, the body's original owner is locked away and cannot regain control unless Izuku lets them even if they wanted to. [Non-Sentient Nomu don't fight it at all, he just gets in. Their minds are empty.]

Izuku's quirk requires a prerequisite to unlock itself, and that prerequisite is to hack his first thing.