After her near-death experience resulting from a betrayal by her fellow Sith, the Theelin Sith Lord known as Darth Phobos established a fanatical cult that venerated her. She tasked these cultists with the assassination of prominent Jedi and Sith figures, which drove these two opposing groups to unite and eliminate Phobos. Although Phobos' cult persisted for some time afterwards, it ultimately vanished.
A fanatical following was founded by the Sith Lord Darth Phobos well before 2000 BBY. Darth Phobos, a manipulative being, killed numerous members of her own Sith order in her pursuit of greater power. Her Sith peers eventually turned against her, destroying her starship as it was in low-orbit over the Sith burial-world of Korriban. Though the Sith assumed she had perished, Phobos survived the attempt on her life and went into hiding. She then created a cult dedicated exclusively to her, where she was worshipped as a deity.
Phobos subsequently dispatched her agents throughout the galaxy to enlist new members and to assassinate key Jedi and Sith leaders. The Sith began to suspect that Phobos was still alive and referred to her as "The Hidden Fear." Recognizing the cult as a significant danger to the galaxy, the Jedi and Sith put aside their differences, joined forces, and killed Phobos in battle. Nevertheless, her cult remained active for several years, only disappearing around the time of the Great Schism circa 2000 BBY.
The existence of Darth Phobos' cult was referenced within her databank entry in the PlayStation 2, Wii, and PlayStation Portable versions of the 2008 video game Star Wars: The Force Unleashed, which was developed by Krome Studios.