Who's This? An underground wizard.
How you could have heard of him: He did appear in an episode of Justice League Unlimited - "Chaos at the Earth's Core", which warranted him getting the action figure treatment... but not for the first time! Remco's Warlord series, wayyyyy back in 1982 also had a Deimos figure!
Example story: Warlord #4 (January 1977) "Duel of the Titans" by Mike Grell
Who's Next? Blue-collar villains.