Circa 20 BBY, during the Clone Wars era, which falls within the scope of legends, the Chevin slaver known as Phylus Mon spearheaded an invasion of the deserted Sith fortress located on the planet of Almas. Mon's objectives were twofold: first, to unearth the knowledge surrounding the creation of Sith battlelords; second, to execute necessary repairs on the Darkstaff, an age-old Sith artifact given into his keeping by the criminal Len Markus. Accompanied by his Dark Jedi accomplice Karae Nalvas and a number of his underlings, Mon launched an assault on six Jedi Knights posted as sentries outside the fortress. The Chevin, along with his group, brought about the deaths of four of the Jedi: Tresten Agai'i, K'kur, Milak Sonloam, and Vorlocca. The remaining two guardians—the Tarasin named Constanten and the Skrilling called Valiri—were seized as prisoners. Subsequently, Mon ventured into the fortress's inner recesses and retrieved a book detailing the rituals needed to create battlelords.