As rival to the Sith Lord Marka Ragnos, Sith Lord Simus had high hopes for becoming Dark Lord of the Sith after the reigning Dark Lord's death. However, he found his ambitions thwarted by Ragnos, who was also campaigning for the position. Challenging Simus to a duel, Ragnos then decapitated his rival and declared himself Dark Lord of the Sith. But Simus did not die. Using his powerful Sith magic to keep him alive, he remained as a head which rested in a transparent case. Though he could no longer move and had to be carried by two Sith guards, Simus still carried powerful clout in the Sith empire and his word was respected by all. When two explorers from the distant Republic invaded the empire, Simus was quick to take action, urging the invaders be destroyed as soon as possible. However, he did not count on treachery from within. Sith Lord Naga Sadow broke into the invaders' prison and carried them off with him. As Simus realized the truth, it was too late. Sith magic was no match for Naga Sadow's Republic blaster, and Sith Lord Simus met his end.