An alien villain from the planet K-Shazor, whose mutant brain gave him psi-powers of telepathy, mind-control, and telekinesis, along with great intellect that enabled him to create spacecraft and high-tech weaponry. He used these vast powers to become the absolute ruler of his homeworld, but was so despised that when a solar eclipse briefly robbed him of his powers his people rose up against him. Defeated and exiled from his home world, the Brain Emperor came to Earth to conquer it, and proved too great a threat for any one hero. The Fly, Fly-Girl, Comet, Black Hood, and The Shield joined forces as the Mighty Crusaders to defeat him. He would have several more encounters with the group, even killing the member Doc Reeves and wiping the mind of Darkling, leaving her a vegetable.
After his most impressive scheme to conquer Earth, The Emperor was apparently eliminated as a threat, sealed away by and with the heroic Mr. Justice. After many years passed, however, the Emperor reappeared, having gained power over the mysterious Blue Ribbon. With his new powers the Brain Emperor ambushed his old foes (now retired and raising families) at a reunion, apparently killing Fly-Girl, Comet, Fireball, The Web, Pow-Girl, Jaguar, and Steel Sterling. The Shield, however, succeeded in saving Steel Sterling, Fly-Girl, Comet, Pow-Girl, and The Web's children, Fireball's nephew, and Jaguar's protege. The teens followed in their elders' footsteps, becoming the New Crusaders and swearing to bring the Brain Emperor to justice.