"My Master prefers to remain in the shadows, but do not doubt his power—nor his ability to reward success."
―Emic Sandor[src]

Darth Charnus was a male Human Sith Lord in the resurgent Sith Empire, and the right hand of Darth Decimus. He lacked his superior's cunning, but made up for it with his cruelty. Even among the Sith, his viciousness was remarkable, particularly when interrogating helpless prisoners.

His penchant for extracting information had served him well, as he was often assigned to investigate secret organizations and societies within the Sith that might seek to bring the Empire down. One such organization was the Order of Revan. He and his apprentice Emic Sandor sought out this organization's destruction during the Cold War between the Galactic Republic and the Sith Empire. His methods were effective, and his success at rooting out and executing traitors was largely responsible for his current position.

Numerous innocent individuals had suffered at Charnus' hands as well, but he had always managed to keep the collateral damage of his investigations to an acceptable level.

At the start of the Galactic War, Charnus joined the battle at Corellia helping to crush the Corellian resistance.