Drevveka Hoctu was once a great female Human Jedi Knight of the Galactic Republic, until she was consumed by the dark side of the Force many years before the Battle of Naboo. She wandered the galaxy until she ended up on Thule, and eventually became the headmaster of the Sith Arts Academy.
She was feared by her students, living up to her reputation as a cruel master, and was known to have forced her students into the deserts of Thule on long, relentless training sessions that forced them to rely on the dark side for strength.
Despite her reputation and skills, Hoctu was never given a rank higher than headmaster. As a result, she vowed to one day make her superiors pay for this humiliation.