Mano is a mutant, born with the power to disintegrate anything that he touches with his right hand, with his "anti-matter touch". Hating his people for mistreating him, Mano decided to destroy them all by touching the ground, and, "straining his power to the utmost", he obliterated his planet, causing it to explode. Considered one of the worst murderers in the Galaxy, Mano was recruited by the Legion themselves to help them defeat the Sun-Eater, after which he continued his criminal career, mainly as a member of the Fatal Five.
His planet's atmosphere is hostile to most living things, and he must wear an environment suit to breath the air on foreign worlds. The dome on his head blocks out his face, so his face is only seen as a silhouette.
Mano has to continue wearing his spacesuit because he can't breathe the atmosphere of most other planets. The suit's helmet obscures his face so that it can only be seen as a silhouette.
Mano appeared in Justice League: Unlimited as a member of the Fatal Five. He battled Green Arrow, Captain Atom, and the Legion of Super-Heroes. During the battle, he made a hole in the floor and was defeated.
Legion of Super-Heroes
Mano appeared in the Legion of Super-Heroes series and was again featured as a member of the Five. In the series his face seemed to channel his disintegration power.