|Jafar says: Read my lips and come to grips with the reality!|
Darth Arctis is a Sith Lord of the resurgent Sith Empire and Dark Council member during the Cold War. At one point during the Cold War, the forces of his fellow Councilor Darth Hadra—the head of the Sphere of Technology but also the ruler of Droumnd Kaas—discovered an ancient Sith shrine outside Kaas City and tried to claim it. Arctis quickly challenged Hadra's claim, saying that the shrine fell within the bounds of his Sphere of Ancient Knowledge's influence. He then began to "negotiate" with Hadra for control of the shrine.
After the Sith Lord, Darth Skotia was killed in suspicious circumstances and Darth Thanaton wished to punish the most likely perpetrator, Darth Zash, this Dark Councilor sided against Thanaton and supported the Dark Council in raising Zash to Skotia's former position.
In circa 3,641 BBY, Darth Thanaton acceded to the Dark Council after this Sith Lord's sudden death. While never outright confirmed it's implied that Thanaton killed him.