Taselda, also called Sel, was a Human female of considerable age, having lived for centuries. During the final decades of the Galactic Republic, she served as a Jedi Knight. However, she succumbed to the dark side of the Force and descended into madness during a mission on Nam Chorios. To prolong her life for centuries, Taselda consumed the droch insects native to the planet. She possessed a lightsaber, crafted by her and at least four hundred years old, which was ultimately destroyed in 44 ABY. Sometime during the era of the Galactic Alliance, Taselda was found by the Theran Listeners, who healed her, restoring her sanity and allowing her to age normally.
Approximately four hundred years before the Great Jedi Purge, Taselda was born to Human parents hailing from both Alderaan and the Hapes Consortium. Her Force-sensitive nature was recognized, leading to her enrollment at the Jedi Temple on Coruscant for training in the Force. She spent many years at the Temple academy, eventually graduating to become a Padawan under a wise Jedi Master. After passing her Trials of Knighthood, Taselda enjoyed a fulfilling existence as a young Jedi Knight, serving the galaxy from the capital world. When the Jedi High Council assigned her to a mission to the planet Nam Chorios alongside the senior Hutt Jedi Beldorion, Taselda accepted without hesitation and embarked on a shuttle to the remote world.
The Jedi struggled on the volatile world due to a lack of emotional stability, making them unable to withstand the intense Force surges that made Nam Chorios so perilous. Beldorion channeled his avarice and lust for power into dominating the planet, causing Taselda to lose control and succumb to the dark side, driving her insane. After losing her lightsaber in a battle against Beldorion, Taselda retreated into poverty, gradually recovering from her severe injuries. She established a residence in the "Newcomers" area of the capital city, Hweg Shul, and began consuming the local drochs, which prolonged her youth for centuries. However, consuming these dangerous insects caused her mind to deteriorate rapidly as she absorbed the memories of the drochs' hundreds of victims.
While the Hutt governed the world, the Great Jedi Purge, orchestrated by Darth Sidious, the Dark Lord of the Sith and the new ruler of the Galactic Empire, swept across the galaxy. Isolated from the purge, the Dark Jedi of Nam Chorios remained unaffected by Jedi concerns until thirteen years after the Battle of Yavin, when Callista Ming, a Jedi Knight, arrived to investigate the planet. Upon encountering Taselda, the madwoman persuaded Ming to assist in overthrowing Beldorion, a task that proved too difficult, resulting in Ming's imprisonment. Shortly after Ming's defeat and capture, Luke Skywalker arrived in search of her. Recognizing his superior Force abilities, Taselda approached him, attempting to manipulate the young Jedi using a combination of mind-altering substances and her mastery of the Force. This ambitious scheme failed against the powerful Jedi, forcing Taselda to retreat into hiding.
Without her interference, Leia Organa Solo, an untrained Force-sensitive, defeated Beldorion, liberating the world. The New Republic deployed several NovaGuns in orbit to prevent the spread of the Death Seed plague, which was transmitted by the droch, and continued to monitor the planet's economic development and the welfare of its inhabitants. This was advantageous to individuals like Taselda, as it promoted the prominence of the Theran Listeners, a group of Oldtimers who employed unique Force techniques to communicate with the native Tsils. When approached by the Listeners, Taselda agreed to undergo a specialized form of mnemotherapy that ultimately restored her mind by suppressing the horrific memories she had acquired from consuming drochs. Recovered from her encounter with the dark side, Taselda became an active Listener herself, earning the respect of her peers and becoming a well-known figure in Hweg Shul.
Thirty years after Beldorion's reign ended, Luke Skywalker, now Grand Master of the Jedi Order, returned to Nam Chorios. Accompanied by his son, Ben, and the Sith Vestara Khai, Skywalker was directed to Taselda in his search for the dangerous dark side entity Abeloth. Although Taselda did not recall her previous encounter with Skywalker, she welcomed them into her home and recounted the events that had transpired on the planet. Unaware of Abeloth, Taselda rejected Skywalker's suggestion to flee the world until the entity was dealt with, believing that the creature's dark side power would overwhelm her. Instead, Taselda opted to assist the Jedi, providing Skywalker with a mnemonic key that would induce a state of hypnosis in her if he needed reassurance about her mental state. Remaining in Hweg Shul as Skywalker departed to investigate a disappearance, Taselda, along with all the Listeners present in the city, fell under Abeloth's influence.
Waiting in her house, Taselda was instructed to act normally when the Skywalkers returned and to sound an alarm that would alert Abeloth to her location. Having recovered her lightsaber long ago, Taselda greeted the Jedi in her living room upon their return. Sensing something amiss, Skywalker sang an old Alderaanian lullaby, the mnemonic key Taselda had mentioned earlier, and placed the elderly woman into a trance. Sel revealed her role in Abeloth's scheme to the Jedi; Skywalker then put her to sleep and erased her memory of their visit. Upon awakening, Taselda followed Abeloth's summons to an old pump station in the Crystal Valley, where she fell into a deep, agonizing slumber as Abeloth consumed her life force. After a brief confrontation with Skywalker, Abeloth's control over the Listeners and Taselda was broken, and she resumed her normal duties in Hweg Shul.