Vitiate

Vitiate was an immensely POWAHful ancient Sith Lord from before the time of Revan. Originally the result of an affair of the ruling Sith Lord of the simple farming world of Medriaas, he eventually killed his father and took over the planet. He never participated in the Great Hyperspace War and at the war's end, he gathered the Sith survivors and used them to found a new Sith Empire on Dromund Kass. For 1,000 years, he consolidated his power while also founding the Eternal Empire on Zakuul. Then he sent his Sith Empire to attack the Republic. He was eventually killed when he commenced a ritual to end all life in the galaxy to make himself immortal. Then Kyle Katarn arrived and said, "Gotta stop ya right there buddy" and then shot him with the Bryar pistol and singlehandedly ended the life of Vitiate.