Korelei was a Keshiri Lord of the Lost Tribe of Sith, identified as female. She ultimately became a host for Abeloth, meeting her end at the New Jedi Temple when both Abeloth and the Lost Tribe of Sith faced defeat.
Korelei had risen to the position of Sith Lady by the time of the Lost Tribe of Sith emergence. After Abeloth gained control over the Lost Tribe and the Galactic Alliance, Korelei's role involved torturing Wynn Dorvan under Abeloth's command, a process that lasted for over a month.
Not long after the Jedi initiated the Liberation of Coruscant, Korelei engaged in discussions with Abeloth concerning the Lost Tribe's casualties. Upon learning that the Jedi had managed to eliminate approximately one thousand Sith, Abeloth instructed Korelei to eliminate all Jedi by the following dawn. Korelei countered that this was unfeasible, as they had not captured any Jedi, and informed Abeloth that Wynn Dorvan, then serving as her advisor, was withholding information about the Jedi. Korelei proposed revealing the Sith's presence to the citizens of Coruscant, but Wynn argued against this, stating it would incite open rebellion. Korelei attempted to assassinate Wynn with her shikkar, but Abeloth intervened, agreeing with Wynn that civilian deaths were not in their best interests. Wynn suggested to Abeloth and Korelei that the optimal strategy would be to bait the Jedi to the Sith-controlled Jedi Temple. Following the death of High Lord Ivaar Workan, she was chosen as one of Abeloth's host bodies, subsequently becoming High Lord herself.
Korelei possessed sufficient strength to achieve the rank of Sith Lord within the Lost Tribe. She demonstrated proficiency in Force torture, which she employed against Wynn Dorvan during his imprisonment. Furthermore, she had the ability to use the Force to delve into an individual's mind. Later, as a host of Abeloth, Korelei exhibited the ability to shield herself from a mine explosion. Korelei also possessed skill in the use of Force lightning, which she unleashed upon Jedi during the Liberation of Coruscant.