Darth Vitus

Darth Vitus was a Sith who lived long before the Old Sith Wars.

Biography
Vitus established a compound on the Outer Rim moon of Oricon. There, he experimented with Sith alchemy, eventually creating monsters steeped in the dark side of the Force. While the location of the moon was lost to the galaxy at large, its location was recorded in a holocron, eventually leading a group of Sith to the planet many years later.

Behind the Scenes
As he lived before the Old Sith Wars, Darth Vitus may have been one of the first Sith to use the Darth title.