MHA Story And Quirk Ideas

Quirk: Devour

Izuku's quirk is Devour. It is a strength/stockpile quirk that uses food as fuel. In order to even get an hour out of his usage he needs to eat 5× the amount of a normal person of his age at the time. Thankfully it has a stockpiling aspect that saves the energy he doesn't use while his quirk isn't in use. Time to elaborate more without the fancy word talking now.

When Izuku eats the normal amount a person without Devour would eat his stomach is tecnically already full, however he just can't feel it. His body is still sending out signals to his brain that he's hungry. When he overeats his stomach dramatically increases the rate at which it processes food, sending the correct nutrients to his body. However once it does and it crosses the border where it would start giving him fat, instead of doing so his quirk sucks up all that nutrients and turns it into raw, unbridled power that could rival the strength of the 9th holder of One for All. All of this, of course, comes with drawbacks but I'll get into those later. The strength and speed don't come with drawbacks at all however.

By overeating he gets energy. That energy is then stored for later use, and will only grow the less it is used. When used however, it starts shrinking. So Izuku has to play a balancing game of how much to eat vs how much to use.

Drawbacks

While his stomach is sped up his bowels aren't. This means that he unfortunately gets constipated easily. It's unavoidable. As a result he avoids cheese and easily stoppable foods.

Izuku is never not hungry. The result of not feeling that you're full is the cause of it. His stockpile expands infinitely so he will never know what being full feels like unless his quirk is erased. If he does get it erased however he becomes very emotional. I mean, imagine never knowing anything but eternal hunger and then suddenly feeling full for the first time since you were 4? You'd probably cry too.