Stefan Thomas, also known as Darth Clavis later by the dark side Force-sensitive community as well as in secret by darksiders loyal to Marcus Lai, was a former Jedi apprentice and betrayed the Jedi to become a Dark Lord during the Rise of the Galactic Empire. Later it is revealed that he was to be the Sith'ari and would become the strongest Darksider in history, becoming one of the greatest threats to the Chosen One and Jedi, as the companion and enforcer of The Fallen as described briefly in the Prophecy of Genesis.