In Challengers of the Unknown #14 (April 1960), our heroes get a new long-standing nemesis: Multi-Man. Mult-Man starts out as Duncan Pramble, an archaeologist’s assistant who steals away and drinks “liquid light” while on an expedition with the Challs. Now every time he dies, he is resurrected with a new random power – how convenient. He starts with the ability to focus energy beams, after being cornered by the Challengers and dose with an “antidote” that takes away his power, he willingly dives of a cliff, presumably dies, and is resurrected with aquatic powers.
After getting cornered again and dosed with another vial of the antidote, he dives into an area of explosives and is re-born again, this time with Avian powers of flight and defying gravity.
While the original concept of Multi-Man is kind of unique concept (and reminiscent of the future Dial H for Hero), the internal motivation of this character seems to be “I’m a villain and I’m going to fuck shit up for the Challengers”. Like it’s not even clear he’s going after power or riches or whatever, just “I’m going to oppose the heroes”.