Superman: The Animated Series Season 1 Episode 7 The Way of All Flesh Episode Title:The Way of All Flesh.Episode Description:Thanks to the orchestrations of Luthor, terrorist John Corben becomes Metallo, a skin-covered cyborg with a Kryptonite heart. Luthor then sets the supervillain on a quest to kill Superman, but Corben begins to question his role as Metallo when he lacks any human senses in the progress.