Darth Vectivus

"He developed a strong ethical code before he felt any pull from the dark side. He was an adult, a hardheaded business man with a keenly balanced sense of profit and fairness, and when temptation whispered in his ear he could ignore it easily."

- Lumiya

Darth Vectivus was a Sith Lord from some time before Darth Plagueis' time. He was an administrator of a mine on an asteroid potent in the energy of the dark side that eventually drove him to become a Sith. Even as a darksider he was fair and balanced in all decisions, factors which influenced later Sith such as Vergere and Lumiya.

In 40 ABY, Lumiya took Jacen Solo there to begin his journey to the dark side. It was there that he killed Nelani Dinn, decided to follow the advice of Lumiya, and witnessed a vision of himself as a Sith Lord.