All For One is a mysterious villain who has been orchestrating the events involving the League of Villains behind the scenes, he has killed every. Other user of One For All but All Might and Deku, and his quirk, All For One allows him to steal quirks and keep them or pass them to others, using this he manipulated people into joining him. He is a force to be reckoned with and is pure, unadulterated, evil.