William Hand(DC, BlackHand)

William Hand, aka Black Hand, is a supervillain who constructed a device which drained power from a Green Lantern's power ring allowing it to be used by himself, usually against a Green Lantern. Eventually, after losing his hand to the Spectre, William was experimented upon by alien Kroloteans and he received the ability to consume the life-force of others to reconstitute his hand. His most consistent antagonists are Green Lanterns.