A cold, calculating Sith Lord, Darth Nyriss is one of the most powerful people in the Sith Empire. Ruthless and enigmatic, she is obsessed with manipulation: over the course of the film, she expertly orchestrates a coup to bring down The Emperor by enlisting the help of Lord Scourge (whom she dispatches to deal with most of the actual fighting involved). However, this habit of secrecy and betrayal is also her key weakness: she lacks the strong and steadfast ideological commitment that her Jedi enemies, Revan and Meetra Surik, share, leaving her squabbling amongst her rivals instead of focusing all of her attention on The Emperor.

Nryiss' voice is a low, smooth rasp that is often laden with a shrewd, smug haughtiness.