The Fatal Five.
The Fatal Five was a group composed of five of the most dangerous criminals of the 30th - 31th century.
History
On one occasion, The Fatal Five used psionic mind control technology to force the majority of the Legion of Super-Heroes to launch an assault on the capital world of the United Planets. The assault was thwarted by Legionnaire Brainiac 5, who had managed to elude capture and was aided by 21st Century heroes Supergirl, Green Arrow, and John Stewart.