Let it unfold

Izuku doesn't remember much, but he does remember what All For One did to him. He made him into Shigaraki's soldier. It was the only thing he was good for.

But maybe that wasn't true. Maybe...he could be more. He'd at least give it a shot for his little sister's sake.

OR

Izuku was kidnapped by All For One and forced to become a villain. In that time, he gains a sister and a goal to one day get her away from All For One and Shigaraki. Luckily, the heroes are willing to help.