All For One (Zen Shigaraki)

All For One, real name Zen Shigaraki, is the overarching antagonist in My Hero Academia. He is the founder of the League of Villains, All Might's arch-nemesis, and one of the most powerful villains in the series.

His Quirk, also called All For One, allows him to steal other people's Quirks, use them himself, and even transfer them to others. This power let him amass an enormous collection of abilities over more than a century, making him nearly unstoppable for much of Japan's history as the original "Symbol of Evil."

He is the older twin brother of Yoichi Shigaraki (the first user of One For All), whom he treated as a possession and obsessively tried to reclaim along with One For All itself.

All For One raised and manipulated Tomura Shigaraki (originally Tenko Shimura) as his successor, grooming him to become a vessel for his Quirk and eventually his mind—part of a long-term plan to achieve total domination as a self-proclaimed "demon lord."

In later story arcs, his influence extends through vestiges and possession attempts within Tomura's body, blending their wills in intense confrontations. He embodies cold, calculating evil, viewing everything and everyone as objects to control or discard.