Izuku was always perceived as shy and dismissed by others due to how powerless he was, seemingly having been born with a useless quirk that did nothing. He bottles up the negative thoughts that come to his mind, seeing them as unfit for a hero, but that causes someone else to be born inside of his mind. and on a fateful day, his quirk as well as this new persona emerge

many different people have many different ways of dealing with anger, some people unleash it on the undeserving, some people close themselves off from the thing that made them mad etc. however the worst way to deal with it is bottling up that anger, because no matter how good you are at hiding it your gonna break eventually and when you do. you'll smash everything with you

Izuku Midoriya had always been Quirkless... Or so he thought. In truth, he had been chosen to be the inheritor of more than just One for All. Bullied, tormented, and now faced with certain death and Villains on the rise this part of himself is clawing to get out. In time, Izuku will realise that the Universe is bigger than he realised. After all, he's an Avenger. One day...

Izuku was born quirkless, in a world of superheroes. Berated by his so called friend. "Pitied" by those he loves. With a secret most dangerous to the world, he would become the greatest hero alive, if he control the rage within.