The man who made Magneto, using a method that explains everything Magneto does afterwards.
Sebastian Shaw absorbs and redirects energy and stays young while doing it. He is first shown as Klaus Schmidt, a Nazi scientist interested in what young Erik Lehnsherr can do with metal, and he shoots Erik’s mother in front of him to force the power out. Everything Magneto becomes starts in that room.
Later he runs the Hellfire Club and works to trigger a nuclear war, on the theory that mutants will inherit whatever is left. He manipulates military officials on both sides into placing warheads, and pushes the Cuban Missile Crisis towards the ending he wants.
Minor spoiler
Magneto lifts Shaw’s submarine out of the sea, takes off the helmet that was keeping Xavier out of his head, and holds him still while Xavier freezes him. Then he pushes a Nazi coin slowly through his skull, and takes over the Hellfire Club himself. It is the moment the film stops pretending Erik is going to end up on the other side.