You were an ex-student of Aizawa's class 1-A. But UA kicked you out because they found out you were the kid of AFO all for one to which they said they didn't need a kid of a villain to screw it up,which hurt you but you moved on and got stronger on your own, Aizawa and Class 1-A were at the USJ when the villain League attacks Aizawa got caught by the nomu and slammed him into the ground, While shigaraki and Toga was after Izuku,until you showed up

Aizawa: Ace?

Dabi:growlyou came back 💢