Risstenni, a Wookiee female, resided on the planet of Cularin during the Clone Wars era. Around 21 BBY, her son, Chywarra, was kidnapped by the Wyrd, a group of Tarasin witches who wielded the Force. They transported him to Cloud Mountain, an inactive volcano, and imprisoned him within the Hand artifact, a statue imbued with the Force that enabled its user to siphon power from whoever was inside. Seeking her son, Risstenni journeyed to Cloud Mountain, only to be captured by the Wyrd. They proposed that she take Chywarra's place within the artifact. Accepting their offer, she entered the statue and was killed during a Wyrd ritual. This transformed her into a dark side spirit, who then encountered a group of agents who had arrived at Cloud Mountain in search of both her and Chywarra.

During the final years of the Galactic Republic, Risstenni was a Wookiee female. She eventually mated with another Wookiee and gave birth to a son, named Chywarra. Approximately in 21 BBY, the family took up residence in Kiirloor, a Wookiee settlement established on the planet of Cularin after the death of Jedi Master Kirlocca, a Wookiee. However, the Wyrd, a collective of Tarasin witches of the Force inhabiting Cularin, opposed the Wookiees' presence in Kiirloor. One morning, two months following Kiirloor's founding, the Wyrd abducted Chywarra. Their plan was to utilize the Hand artifact, a Force-imbued statue shaped like a hand, to draw power from him. The Wyrd's intention was that this would trigger an eruption of Cloud Mountain, the dormant volcano, thereby destroying Kiirloor.
Upon awakening and discovering Chywarra's absence, Risstenni initiated a search. After some time, she located a ryyk blade toy that belonged to her son, and she left it by a tree near Cloud Mountain as a signal for anyone tracking her and Chywarra. Continuing her search, she spotted Chywarra being carried up Cloud Mountain by a member of the Wyrd. She then ascended the volcano and began searching for her son within the mountain's tunnels. Ultimately, she came across a vast cavern that served as the headquarters for a Wyrd enclave situated inside the mountain, and she began observing the Tarasin within the chamber. However, overhearing Wyrd members discussing Chywarra's survival of a session inside the Hand artifact, Risstenni, enraged, emerged to confront the Tarasin. Xinishia, the group's leader, threatened to kill Chywarra if she attempted to fight them. Xinishia then used the Force to compel Risstenni to sit down. Xinishia proposed that Risstenni take Chywarra's place inside the statue during the Wyrd's upcoming ritual. Seeing no other way to save her son's life, Risstenni agreed.
The Tarasin allowed Risstenni to bid farewell to Chywarra before assisting her into the artifact's thumb. The Wookiee clawed at the device's interior, but was unable to escape due to its highly polished, smooth material. As the Tarasin commenced their ritual, Risstenni was overwhelmed by a sensation of something inside her attempting to tear her apart, causing her to lose consciousness. The device drained her life force, resulting in her death and transformation into a dark side spirit. Upon regaining consciousness, Risstenni discovered her changed form and ability to move through the statue's walls. Though considering seeking help, she decided to remain within the enclave, unwilling to abandon her son. The Wyrd, ignoring her in her new form, allowed her to overhear their plan, revealing their intention to destroy Kiirloor.
When the Wookiees of Kiirloor realized Risstenni and Chywarra were missing, they dispatched representatives to inquire with Mother Dariana of the Tarasin Hiironi irstat about the pair's disappearance. Dariana sent the Heroes of Cularin, a group of freelance agents operating in the Cularin system, to investigate. They journeyed to the tunnels within Cloud Mountain. Risstenni approached them in the guise of a ghostly humanoid, then learned to manifest herself in her Wookiee form. She spoke to the agents, explaining her death and pleading for them to rescue her son. She also warned them of the dangers of continuing through the tunnels. However, while she was speaking, a Tarasin Force ghost attacked the agents, intending to prevent them from interfering with the Wyrd's plans. Risstenni responded by engaging the spirit in combat, allowing the agents to confront Xinishia and the other Wyrd members.
Risstenni was consumed by fury upon overhearing the Wyrd members discussing Chywarra's survival of a session within the Hand artifact, fueling her desire to tear Xinishia's limbs off. She was hesitant to agree to Xinishia's proposal to take Chywarra's place inside the statue, but ultimately conceded, viewing it as the only means to save Chywarra, especially given the overwhelming number of Wyrd members she faced alone. She also feared the Wyrd would again use their Force powers to control her, as Xinishia had done to make her sit down. Risstenni hoped to survive long enough for assistance to arrive. Post-death and transformation into a dark side spirit, Risstenni did not harbor the typical rage of such spirits, due to her self-sacrificing act to save her child.
Ed Gibson created Risstenni for From the Trees, a Wizards of the Coast role-playing adventure within the Living Force campaign. The scenario casts players as the Heroes of Cularin. They have the option to decline Dariana's call for help from the Wookiees of Kiirloor; this choice prevents them from ever encountering Risstenni's spirit. If they accept the assignment, they can attack Risstenni upon their initial encounter, before she manifests as a Wookiee. They can then destroy the spirit using the Force Light power. Should the players speak with Risstenni and decide not to proceed further into the Cloud Mountain tunnels, she understands and prioritizes their warning the Wookiees of Kiirloor about the Wyrd's plan over rescuing Chywarra.
If the player characters reach the Wyrd enclave's headquarters, they are confronted by Xinishia and the Wyrd, who attempt to negotiate a deal. The Wyrd offers to free Chywarra and allow the players to leave unharmed in exchange for the players' promise to convince the Wookiees to relocate Kiirloor. If the players agree, Risstenni, upon their departure, defeats the Wyrd spirit she had been battling and thanks the players for saving her son. Risstenni remains close to Chywarra throughout the remainder of the adventure, and the players can then suggest that Chywarra enroll at the Almas Academy, a Jedi academy on the planet Almas. If he chooses to attend, Risstenni's spirit accompanies him to the academy.