Betrayal to the Sith

During, the event's known as Order 66, a former Sith knight, under Darth Tyranous, whom left the Sith for a better employment. In the works of bounty hunting, made one final job as a Sith before he went off the radar. He does something, that no Jedi would ever expect a sith to do, well.. mainly the blinded jedi, but the Sith help's a Padawan escape the purge. And find a new home.