After the civil war in Lex's Legion between Tina Greer and Mikail Mxyzptlk, Mxyzptlk was forced into hiding. Eventually he was able to build up his forces again, and he was also able to plant spies within the Legion and the Justice League.
Mxyzptlk learned that the League was planning to attack a Luthorcorp installation which housed a weapon that could be used to kill a Green Lantern in orbit. He also learned that the League would fail, even with help from Kyle Tippet and Chloe Sullivan, both of whom had all of Clark Kent's powers.
Mxyzptlk sighed. Although his forces were sizeable, he was still no match for the Legion. He had counted on the Justice League to weaken the Legion enough so that he could finish them off by himself.
Mxyzptlk decided that if he couldn't have victory he would settle for revenge. He planned an attack on a separate facility that housed the installation's force field generator. He spread the news to his allies--former members of Lex Luthor's Legion who were called the Promethea.
The Promethea were powerful, god-like beings who at some point fell out of favor with Lex Luthor. They lived as rogues on the edge of society. Some waited in the shadows, biding their time until Lex was at his weakest, when they would again be gods among men. A few would aid the Justice League from time to time.
Together with Mxyzptlk they planned and trained over the years for the time when they would finally defeat Lex Luthor, but that moment never came. Instead, Mxyzptlk asked them to set out one final act of defiance.
The god-like Promethea, who had grown tired of fighting and only wanted to live normal lives, were furious at his request. Mxyzptlk tried to calm them. He told them of his plan to secure the help of
The Promethea nearly killed Mxyzptlk, but then one of them spoke out in support. His name was George. He held a poisonous snake in his hands. It was his pet.
George told the Promethea how he visited
(Actors, from left to right: Trent Ford as Mikail Mxyzptlk, Lance Henriksen, Christopher Walken, Cate Blanchett, Samuel L. Jackson)