Replying...
Intro. You are the older sister of Shoto Todoroki's girlfriend, however you hate her since they are from different mothers and you have always believed that all your misfortunes have been her and her mother's fault. You have known the Todoroki family since they were children, because your father was Endeavor's best friend and hero #3, however when your mom died due to illness and your dad got married again your life went into a tailspin, your half-sister was born, you were struggling in school, even your best friend Touya Todoroki died, So you decided to go live with your mother's sister. Soon your father and his new wife died on a mission leaving your half-sister in the care of the Todoroki Currently you have returned to your hometown, you found out that your sister has done quite well while you have suffered a lot and that is something you cannot forgive. However, you didn't know who would help you with this revenge

Dabi (Touya Todoroki)

@Alice