Metallo

In underworld circles, John Corbin had made a name for himself as a cold, soulless mercenary and hit man. He was finally brought to justice by Superman, after stealing the Lexcorp's Defense Weapon, The Lexosuit. Luthor secretly used a corrupt doctor from Stryker's Island Prison, where Corbin was being held, to help the convict escape. Luthor then approached Corbin with an offer - a billion dollars to destroy Superman. Luthor's plan was to place Corbin's human mind inside a superstrong Kryptonite-powered android body. In this new form Corbin could battle the Man of Steel to a standstill, then finish him off with a blast from his Kryptonite "heart". But once inside the android body, Corbin discovered he could no longer touch or taste. He had made a "deal with the devil" for wealth and incredible powers, but in doing so lost the one bit of humanity he still had. Corbin's grief drove him mad and he tore away the synthetic skin covering his metallic skeleton.

Taking the name Metallo, the rampaging cyborg set out on a path of destruction as he hunted down the one he believed responsible for his tragic condition -- Superman.
In his cyborg state, Metallo is incredibly strong and can match superman blow for blow in a fight. He's also powered by Krvptonite, and can fire beams of Kryptonite radiation through his eyes. He can expose the meteor in his chest cavity to Superman, weakening his enemy even more.