Twenty-eight year old Janus was originally a double agent. As a new T.H.U.N.D.E.R. recruit
, he is actually in the service of the dread Warlord, assigned to destroy T.H.U.N.D.E.R. headquarters. Looking to win the confidence of the agency hierarchy, he agrees to try a helmet designed by the late Dr.Jennings
. No one at T.H.U.N.D.E.R. knows what it will do, and when Janus slips it on he acquires the ability to read minds, perform computer-fast calculations, feed on the strength of others--giving him their cumulative might--and both harness and radiate "mental energy" to manipulate solid objects. What Janus doesn't realize is that the helmet also works on the subconscious. Forcing the wearer to do good. Even without the helmet, Janus was a powerful figure, and expert in wrestling and karate. He died by being shot a half-dozen times in the back by one of the Warlord's minions as he tried to warn his fellow agents about an ambush.
John Janus' Legacy of being Menthor has been passed down to many different wielders of the helmet. From an unknown female who came into possession of his helmet and a mental echo of John (see the story Counterattack in Blue Ribbon Comics 12) A more dark and grim African-American Menthor (In Omni-Comix #3) and finally The Salesman in the current DC comics series