The alien supervillain known as Despero is one of the deadliest foes the Justice League has ever faced and one who has gone through almost as many transformations as the team has over the decades. An alien tyrant who debuted in Justice League of America #1 (by Gardner Fox and Mike Sekowsy), Despero was the dictator of the planet Kalanor before some escaping rebels brought the Justice League to his attention. This triggered a never-ending feud between the heroes and the tyrant, and sometimes the team has found it necessary to employ drastic measures to stop the powerful villain. At one time, the League even swapped his body with their robotic ally L-Ron, who would later join the Justice League Task Force, putting his vast powers in service to the good of the DC Universe.
During their first confrontation, Despero, armed with his hypnotic third eye, managed to defeat the Justice League and banish them to different worlds. But he underestimated their resilience and the heroes returned to defeat and imprison him. This marked the beginning of a decades long blood feud, with Despero even physically altering himself to better match his more physical foes like Superman and Wonder Woman.
Each time Despero returned it took everything the League had to defeat him. One time even culminated in the Martian Manhunter using a sacred Martian rite known as "Mayavanna" to give Despero the reality he desired: one where he killed the Justice League and destroyed the Earth. Satisfied with the illusion, Despero reverted to a fetus and the League placed him in the care of Manga Khan. However, the powerful alien eventually returned in his adult form, angered by the deceit he had suffered and the humiliation at being Khan's captive.
This would lead to a confrontation between him and the Justice Leagues of America and Europe. The Green Lantern Kilowog, desperate to end the battle as Despero held off two separate Justice Leagues, took advantage of the slave collar still around the alien warlord's neck. He used it to switch Despero's mind with the robotic Justice League ally L-Ron's, trapping the villain inside the significantly weaker robot's body, while L-Ron assumed control of Despero's body.
Despero's mind was transformed into a psychic entity after the robot body was destroyed, and L-Ron joined the Justice League Task Force, intending to put Despero's powers to good use. But the villain's presence still lingered. Even though L-Ron was in command of the body, the residual psychic traces of the powerful alien warlord compelled L-Ron to kill innocent people, an urge he constantly resisted. But his time as a Leaguer was well-spent, as he participated in a multi-League effort to repel the Overmaster, an alien threatening all life on Earth. Unfortunately, Despero would not remain a psychic entity forever.
The former tyrant would inevitably want his body back and attempted to seize control of it from L-Ron. He succeeded for a time, resuming command of his powerful body before Supergirl helped L-Ron banish Despero from his mind again. The alien tyrant then made multiple attempts to find a new body suitable for him to inhabit, ranging from Superboy to the Martian Manhunter before finally being restored to his very first form when he was pulled out of time by Mister Mind, an enemy of Shazam.
From there, it was only a matter of time before he reclaimed his more physically imposing form. The villain would have several misadventures that would see him become more powerful than ever. He helped create an alternate reality with Mister Mind and even briefly attained a god-like status before being defeated by the Justice League. And while he hasn't made any significant appearances since the "Forever Evil" storyline, Despero remains one of the single greatest threats to the Justice League and one that will never relent.