The Brotherhood of the Q raised Uno to wear the helmet of Quetzalcoatl and defend the city of Vanity and the world against the shadow god Tezcatlipoca. When Uno arrived in Vanity, however, he encountered a vigilante named Bloodtype, aka Dr. Curtis Falconer. Bloodtype died after their battle, but not before he told Uno that he was about to start work at St. Bartholomews Hospital that very day. Deciding he needed a civilian identity, Uno impersonated Falconer, protecting Vanity as a Super Hero later dubbed Aztek by the press. After team-ups with Green Lantern and Batman, Aztek briefly joined the JLA but died attacking the living planet Mageddon, the supposed second coming of Tezcatlipoca.