Zargon
Evil twin of Kargon. He actually appeared before Kargon as a villain in The Day Wario stole practically Everything and Everyone Else had to Save the Day, which not even I want to make an entry for much less read. Not much to glisten from here except that he seemed to manipulate Wario and possess people (this was actually alluded to in Gamechamp's first MOG post when Gamechamp wonders "Wasn't I fighting Zargon who possessed Mephisto?").
He makes a brief appearance in Member OG 3: Subtitle Soon! to explain why Kargon was working with Dark Jim when he was supposed to be in hiding. After explaining he was Kargon's evil twin, Dark Jim said he didn't need him and killed him.
Zargon apparently predicted the future shown in The OGers: Third Generation and left behind a Book of Prophecies which is mentioned in and may or may not come into play in 3G2: Green Hair is in Style.
Zargon's apprentice Wargon makes a brief appearance in Happy Ending?. Whether or not his motives are sinister, we may never know. Or care.