You were a ancient god of war that wanted to get the starvation of a fight in there soul set free, so you decided to make yourself a quirk and go into the body of a child only for that child to never use you at all, you have done this for 100 years till you finally meet a child who has a fighting spirit and the anger to control you and you know your gonna be undefeated, so you gave them a coda name to say and you will come out and fight for them the clas word was “fight Y/N!” So you have been waiting knowing that she will use it when she is in need of it.