Around 21 BBY, as documented in Legends material, the female individual named Tarasin met her death and was subsequently transformed by the Wyrd witch coven into a dark side spirit. This spirit then became a guardian of a Wyrd enclave situated on Cloud Mountain, a volcano located on the planet known as Cularin. When a band of freelance agents dared to venture onto Cloud Mountain to confront the witches, the spirit attacked them. Ultimately, however, the Tarasin spirit was challenged and ultimately defeated by Risstenni, the Wookiee Force ghost.
During the Clone Wars era, specifically around the time of 21 BBY, a Force-sensitive female Tarasin resided on the planet of Cularin. She developed into a Force Adept. The Wyrd, a coven comprised of Tarasin Force witches, targeted her and placed her within the Hand artifact, an ancient dark side artifact located in a cavern on Cloud Mountain, Cularin's dormant volcano. The Hand artifact allowed its users to amplify their power by draining the life force of a victim placed inside. Tarasin was subjected to this process, resulting in her death and subsequent transformation into a dark side spirit. The Force Adept's ghost remained at the Wyrd enclave on Cloud Mountain, and she served the witches as a guardian of the dark side relic that had caused her demise.
After the Wookiee colony of Kiirloor was established near Cloud Mountain, the Wyrd plotted to use the Hand artifact to trigger a volcanic eruption, destroying the settlement. A group of freelance agents arrived at the Wyrd enclave to oppose the witches. The Tarasin spirit was determined to prevent the operatives from interfering with the Wyrd's plan to activate the volcano.
As the agents spoke with Risstenni, a Wookiee who had become a Force ghost due to the Hand artifact, the Tarasin spirit appeared. She attempted to entice the operatives to the dark side by lamenting her fate and the fate of other victims of the Hand artifact, challenging them to attack the Wyrd witches. A battle ensued between the Tarasin spirit and the freelance operatives, during which the Tarasin attempted to possess one of the agents. Eventually, Risstenni intervened, attacking the spirit and allowing the agents to proceed and confront the Wyrd witches. The two spirits engaged in combat, and the Wookiee ghost ultimately defeated and vanquished the Tarasin spirit.
The Tarasin spirit was skilled in using the Force to cast illusions and manipulate the minds of others.
The Tarasin dark side spirit made an appearance in From the Trees, a 2003 roleplaying adventure written by Ed Gibson. This adventure is set within the Star Wars Legends continuity and is part of RPGA's Living Force campaign. In the adventure, players take on the roles of the freelance agents who encounter the spirit on Cloud Mountain. The Tarasin ghost attempts to possess the player character who is most concerned about the plight of the Wookiees of Kiirloor, or alternatively, the player character who is most moved by the spirit's speech to the agents, or even just a random member of the group. The Tarasin's name is not mentioned in From the Trees.