Teyjean was a female Fosh Sith Lord who served Sith Overlord Vedya Gasald during the New Sith Wars. Publicly, she was a junior member of Gasald's council, but without a portfolio of responsibilities; in secret, she was one of Gasald's more important agents, supervising internal intelligence and acting as a sort of secret police commander within Gasald's fief. Apart from Gasald herself, only Halicon Karzded and Darth Vaszas truly apprehended her abilities and importance; after their deaths on Milagro, Teyjean became even more of an enigma to her fellows, who dismissed her as a cipher. Even Celop Faro, Gasald's master of (foreign) intelligence, had no inkling of Teyjean's work. Teyjean thought little of most of her master's council Lords, whom she felt had grown comfortable to the point of indolence in their power.
After the Battle of Eriadu, Teyjean reserved judgment on Darshkére, her master's newest servant; she found him amiable and agreeable outwardly, but sensed he could be both powerful and dangerous at will. After the Battle of Allanteen, Teyjean retreated to Darshkére's territory along with the other anointed Sith Lords, whom Darshkére brought together to decide their next course. As various Sith offered their plans, Teyjean paid closest attention to Darshkére, observing subtle signs that he was manipulating events in his favor.
When Bregin Bymar, Darshkére's foremost Sith Acolyte and de facto apprentice, suggested the Sith elect one of their own as the new Overlord, Teyjean felt her suspicions confirmed. She voted for Darshkére along with all the others, but afterwards met him privately to ask how long he had been planning to become Overlord. Pleased by his response—"the day Vedya anointed me"—Teyjean was relieved to have an Overlord capable of long-term strategizing and delicate manipulations, and pledged her full support to him.