Supernalia is the wife of Nebulon the celestial man (they are both members of the alien race Ul`lula`n.Nebulon had chosen exile before death ,but Supernalia felt that this action brought shame to her and their children so she went to Earth to kill him and restore his " honor".She enlisted the aid of the Defenders (by telling them she was a bounty hunter)and claimed that the Avengers were being mind controlled by Nebulon.She also altered them that Nebulon hid four anti-matter bombs that would destroy the world.Believing her(also being mind manipulated ) they set out for an confrontation with the Avengers .During their battle Supernalia attacked both teams with one of her hubands weapon that was draining their life force.Convinced by the Beast that she was acting dishonorably she withdrew her attack but the weapon was defected by Captain America`s shield causing the beam to hit Nebulon .The beast attempted to help him but Supernalia jumped in the way ,claiming at last they would both die honorably .If  they truly died is still uncertain. 

Creation

Supernalia was created by JM DeMatteis and Al Milgrom in 1982 and first appeared in The Avengers Annual # 11.