Lex Loath

Lex Loath, known (roughly) as "Roast Kuppakalbi" (ロース・クッパカルビ) in Japan, is the leader of the Loath family, a greedy black market financier that has made a fortune with unsavory tactics. He loaned a million Zenny to Teisel Bonne and sent Glyde to get it back from Teisel. With Teisel and Bon Bonne as his prisoners, he uses them and other prisoner Diggers as his workers to uncover the legendary Reaverbot, the Colossus, probably the largest robot to ever be in any of the Mega Man games. Loath is the main boss in The Misadventures of Tron Bonne, using the Colossus against the Bonnes in the end of the game. After the Colossus' defeat, he and Glyde falls in the ocean, and start begging for his life to be spared (probably he can't swim). He and Glyde were then put in jail by Denise.

It's unknown what happened to Loath after The Misadventures of Tron Bonne, but he has a cameo appearance in Mega Man Legends 2 inside the airship King Glydon that looks like a memorial, which suggests he passed away sometime between the two games.

Trivia

 * His English name appears to be based on the supervillain Lex Luthor of the Superman comics appearing in the DC universe. Both even wear similar clothing.