Darth Leviath

Darth Leviath was a male Sith Lord from 377 BBY until 205 BBY. He was originally Dade Leviathan but turned to the dark side when his wife, Skye Raven was killed in 377 BBY. He killed Darth Addus and Darth Ataku in 376 BBY and assumed the role of Sith Master. He then took Darth Ravish as his apprentice. Darth Ravish would become on of the most unknown, yet influencial master in history, as he was the master of Darth Plagueis.

Darth Leviath finally turned away from the dark side and rejoined the path of the light in 205 ABY when Jedi Master Yoda confronted him and beat him in one on one combat.