Neutrax is a survivor of the planet Dryad in the later half of the 30th century. He has the peculiar ability to mentally negate things, including super-powers and brainwave activity. His legs were crushed during the destruction of the planet Dryad, and he used an anti-gravity chair to move. After their attempt failed, the Assassins were imprisoned on Takron-Galtos, but later escaped and joined Nemesis Kid's Legion of Super-Villains.