A Sith demon was once a dead being brought back to life with the Force before achieving oneness with it. These Sith demons were forced to obey the Sith who resurrected them. During the Sith rebellion led by the Dark Lord of the Sith, later known as the Ronin, the witch accompanying him resurrected deceased Sith warriors, creating a demon army that fought alongside the living Sith in their war against the Jedi. During a large gathering on Rei'izu, Kouru, a female Sith and future bandit leader, observed the witch raising demons, noting they were merely fleeting shades lacking free will. Some accounts of the rebellion described this practice as unholy sorcery and a violation of the natural order.
Two decades following the rebellion's end, the Jedi clans and Jedi lords had increased their power. Mirahi, the Ronin's and the witch's daughter, continued her mother's practices. After accidentally killing her mentor, Mirahi revived them, and they became the Traveler. She transformed many dead Jedi into Sith demons, preventing the Jedi clans from recovering the bones of fallen Jedi, leaving battlefields devoid of corpses.
During a skirmish on Genbara, the Ronin fought Kouru and killed her inside a temple. Mirahi resurrected Kouru as a Sith demon to use against her father; however, Kouru demonstrated more independent thought than most demons.