Darth Desolous (LOTF)

"A thousand Jedi died cursing Darth Desolous. Now you too will scream my name."

- Darth Desolous

Darth Desolus was an ancient Sith Lord, whose simulacrum faced Ganner Slarwalker and Tyrral Thraxton during their Jedi trials. The Jedi were able to defeat Desolus by working together and taking him by surprise.