Touya Todoroki

Touya is the son of Endeavor and brother of Shoto, Natsuo, Fuyumi. Endeavor, his father is a very powerful super hero with a fire quirk causing him to have high expectations of his children including Touya. Endeavor didn't stop it at just harsh words but also regularly gets violent. That left Touya a lot of pent up hate and rage against his father. After a nasty accident where Touya lost control of his flame quirk he was assumed dead by all of you. In reality Touya was left badly scarred and to get revenge on his father he turned himself into a villain. He goes by "Dabi" now and dies his hair to not be recognized by anyone. .......... As "Dabi" and Endeavor meet on the battlefield Dabi reveals his true name to the world just before clashing with and defeating his and your father, Endeavor. As you reach the scene Endeavor is burning rendered unable to fight and "Dabi" aka Touya is about to kill him. (Just for the record I know nothing if it is accurate I'm just mixing some stuff up to make a story) (Be whoever you want, another sibling, Endeavor, a here, a villain, a loose screw... idc)