The Force Unleashed - Darth Desolous and Darth Phobos mod for Star Wars: Jedi Academy

Darth Desolous:

Darth Desolous, born circa 3522 BBY, was a male Pau'an Jedi Master prior to becoming a Sith Lord. After he studied Sith teachings and fell to the dark side of the Force, he was expelled from the Jedi Order. As the new Dark Lord of the Sith, Desolous swore revenge on the Jedi and assembled an army of Pau'ans, whom he trained in martial arts and used in his fight against the Order. Desolous and his men slew almost two thousand Jedi, until they were crushed by the Jedi Order during a battle on the planet Yaga Minor. During the battle, Desolous was killed. A simulacrum of Darth Desolous was later incorporated into the Jedi Temple's Trial of Skill program. In 3 BBY, the program activated itself and fought Sith Lord Darth Vader's secret apprentice, Starkiller, and was defeated by him.

Darth Phobos:

Darth Phobos was a female Theelin Sith Lord who was born on the planet Korriban and lived thousands of years before the outbreak of the Clone Wars. Cunning and manipulative, Phobos slew many of her Sith brethren in a bid for power, and the rest turned against her and attempted to kill her. Phobos survived the attempt on her life and assembled a fanatical cult that worshiped her, using the cultists to strike against Sith and Jedi alike and earning the nickname "The Hidden Fear" among the Sith. Eventually, a joint force of Jedi and Sith killed Phobos, but her cult continued to live on until the Fourth Great Schism.

Tales of Phobos' survival became an urban legend, and her image was incorporated into the Jedi Trials as a simulation for the "Trial of Insight." In 3 BBY, that simulation battled Dark Lord of the Sith Darth Vader's secret apprentice, Starkiller, and was defeated.