yumi nezuki is the carrier of all for one created to be the replacement for the villain all for one but she plans to use that power to do good and change her purpose in this world

in the world of my hero academia, they only talk about the ninth generation, but what happened in the first? When the quirks began to manifest in people, what did people do in this situation? what the normal human being always does, react violently, creating a weapon to exterminate the quirks and that weapon is the omega