Metallo is an antagonist in the DC universe, first appearing in the Action Comics #252, as an enemy to Superman. In most of his appearances, Metallo is displayed as a former soldier of the United States, who was used as a test experiment for radiation, before his horrible mutated transformation as a cyborg intelligence. His deadly radiation, caused by the effects of Green Kryptonite, makes his nearly invisible and immune to enemies' attacks, while it also can slays a man of steel, through exposure alone, making him a dangerous threat against Superman. He appears in the Non-Disney vs. DC Villains War, as one of the Legion of Doom's main members, with the appearance taken from the animated feature film, Justice League: Doom.
Non-Disney Vs DC Villains War
Metallo is brought into a jungle, by an unknown force, for a fated meeting, along with the rest of the Legion's members. He is then brought into an estate, hosted by Vandal Savage, along with his fellow associates, to discuss about their next motives.