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 through unsavory tactics. He loaned a million Zenny to Teisel Bonne, and sent Glyde to collect payment. As Teisel was unable to pay back the loan, he and his little brother Bon Bonne were taken prisoner, where Lex forced them and other indebted prisoner Diggers as slaves to uncover the legendary Colossus, a massive Reaverbot of untold power. 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 fall in the ocean, and Lex begins begging for his life to be spared. He and Glyde were soon arrested 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

 * Like many characters in the Mega Man Legends series, Lex appears to have cybernetic prosthetics, sporting a pair of 4-fingered mechanical hands as well as a metal nose.
 * 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.