Another Superman villain who utilises the power of Kryptonite, John Corben was given a heart made of the deadly remains of the Man of Steel's home planet in order to save his life after being mortally injured (though the most recent version of the character actually volunteered). Regardless of how it's happened though, Metallo has always utilised both that and cybernetic upgrades to take it to Superman when they've clashed. While he's a character who has yet to be given a chance to shine on a grand stage - he's more often than not just used as a henchman by the likes of Lex Luthor - Metallo is incredibly powerful and one of only a small handful of bad guys capable of pushing Superman to his limit. He is in fact so powerful that only Superman is capable of taking him down, no easy task when you consider what that Kryptonite ends up doing to him!
