Despero was an extraterrestrial invader who arrived on Earth to combat the Justice League. Despero attempted to convince the Martian Manhunter to help him invade the planet, though the latter declined, and being an ally of the Justice League, helped the heroes stop him. Though defeated, the eight heroes barely managed to stop him. The Manhunter later trapped Despero in a prison on Mars. Despero returned years later and began to systematically target the League, starting with their four newest members, at that point. However, just as he was about to finish them off, the Manhunter returned to combat Despero and quickly dispatched him.