The Cult of Phobos

The Cult of Phobos was a Sith worshiping cult during the Clone Wars. They were formed during the time of Darth Phobos' life until her death where they disbanded. During 20 BBY, a Force User by the name of Adlez would reunite the cult, claiming he spoke to the spirit to Darth Phobos.
The cult was soon disbanded yet again during "The Duel on Hi-Ro" where Jedi Masters Quinlin Vos and Amy fought Adlez, who killed himself to end the ritual to resurrect Darth Phobos, causing total destruction around Hi-Ro's Phobos temple, destroying much of they cult's members and it's armory.
Remnants of the group would reemerge around 19 BBY towards the end of the Clone Wars. Lead by several different priests of the cult, the followers of Phobos would launch a massive operation on the galaxy to spread fear and horror. It would be soon found out their reasoning for such attacks would be appease their dark lord, hoping to aid in her resurrection by strengthening the ritual's process though the fear of the innocents of the galaxy.