Darth Lokess was a figure, either Human or of Sith pureblood heritage, who possessed the rank of Dark Lord of the Sith. She also served on the governing Dark Council of the reconstituted Sith Empire in its initial centuries. Amidst a fierce tempest on the Imperial capital world of Dromund Kaas, Darth Lokess convened the other eleven members of the Council, persuading them to participate in her scheme to eliminate the Sith Emperor. To safeguard against dissent, she positioned a force of devoted Sith outside the assembly. While the eleven other Sith Lords consented to Lokess's plan, their attempt to face the Emperor at the Imperial Citadel resulted in their immediate deaths in a burst of light. Subsequently, the Emperor confined Lokess within the Citadel's lower levels, where she was tormented until she perished.
The character Darth Lokess was referenced in the Star Wars: The Old Republic Encyclopedia, a 2012 reference book.