[gonin]

When the factions of the Sith on Korriban turned on each other after Darth Malak's death and Revan's disappearance, Sion was one of the Sith Lords that escaped to the Unknown Regions of the galaxy. It seemed he had escaped to Malachor V, where he became the apprentice of Darth Traya, a former teacher of Darth Revan when he was a Jedi. For his benefit, Sion was a Sith Marauder.

Sion was a uniquely powerful Sith Lord, having learned the ways of pain in the Trayus Academy on Malachor V. Torturing and killing others helped him enhance his strength in the Force, and his ability to feed on his own pain and hatred made him all but immortal, as when he was struck down, he could always arise, feeding on his agony. He was also a lightsaber master, and arguably the most infamous and deadly Sith Assassin of the era. Sion was known to be responsible for the deaths of countless Jedi during the shadow war waged by himself and Darth Nihilus.

However, the alliance between Traya, Nihilus, and himself could not last forever. Sion and Nihilus attacked Darth Traya at the Trayus Core and as such, exiled her. Sion and Nihilus continued their shadow war by sending assassins after the last known "Jedi"—an exile who had served under Revan during the Mandalorian War. This is from Wookiepedia.

So it says buddy boy escaped from Korriban and didn't die at Malchor 5 during the war. He came back to learn there. I don't think it's Uthar but maybe. Also baldness and deep vocies are pretty common.