Xecr Nist, a Human male, was a Dark Side Adept who pledged his allegiance to Galactic Emperor Palpatine and his Dark Empire regime. After Jedi Knight Luke Skywalker and his sister Leia Organa Solo killed Palpatine in 10 ABY, the Emperor was reborn within a clone body housed in the Emperor's Citadel on the planet Byss. During this time, Nist served Palpatine as one of his personal advisors. Shortly after the Emperor's resurgence, Nist, along with fellow darksider Tedryn-Sha and Imperial engineer Umak Leth, accompanied Palpatine aboard a shuttle to inspect the newest Imperial superweapon, the Galaxy Gun, which was nearing completion in orbit around Byss. As their shuttle circled the Galaxy Gun, Palpatine received news that Executor Sedriss and [Vill Goir](/article/vill_goir]—both members of the Dark Side Elite, an exclusive group of the Emperor's Dark Jedi—had been killed by Luke Skywalker on the planet Ossus. Fearing that Skywalker could overcome him without his Dark Side warriors, Palpatine turned his attention to Nist and Tedryn-Sha. Remarking on their progress in submitting to his will, Palpatine infused Nist and Tedryn-Sha with the dark side, granting them powers akin to Dark Jedi and appointing Xecr Nist as the new Executor to replace the fallen Sedriss. Tedryn-Sha was then made Palpatine's second-in-command.

As the Emperor continued his inspection of the Galaxy Gun with Nist, Tedryn-Sha, and Leth, a shipment of new X-1 Viper droids arrived on Byss, purchased from governor Beltane of the planet Balmorra. Unbeknownst to the Imperials, Beltane had collaborated with the New Republic, allowing them to load the droids with New Republic soldiers. Once the droids were delivered to Byss, the soldiers activated them and assaulted the Emperor's Citadel. The Emperor commanded his adepts within the Citadel to release his chrysalide rancors, which decimated the Vipers, though the New Republic troops managed to escape with the help of local smugglers. Certain that his Galaxy Gun would crush the New Republic despite the enemies' escape, Palpatine instructed his forces not to waste firepower on the fleeing smuggler ships, surprising his newly-appointed Dark Jedi. Instead, Palpatine ordered his new weapon to fire upon the New Republic Pinnacle Base on the moon Da Soocha V.

With Pinnacle Base successfully obliterated by the Galaxy Gun and the remnants of the New Republic scattered across the galaxy, Palpatine was sure that Luke Skywalker and the Jedi he had gathered would flee to the secret location of Leia Organa Solo and her children—the twins Jaina and [Jacen](/article/darth_caedus], whom the Emperor intended to turn to the dark side. Soon, a New Republic pilot named Ntthan was captured by the Empire in an uncharted region of space and brought to Bast Castle on the planet Vjun, where Dark Jedi Kvag Gthull began torturing him to reveal Organa Solo's location. Nist accompanied Palpatine to Bast Castle aboard the Lambda-class shuttle Tridius to oversee Ntthan's interrogation, where he was impressed by the statue of the Dark Lord of the Sith Darth Vader erected by the late Sedriss. Noticing Nist's admiration, Palpatine ordered the Executor to remove the statue. The Emperor then questioned Gthull about the interrogation's progress, and the Dark Jedi revealed that Ntthan had disclosed the coordinates and name of the planet—New Alderaan.

Upon receiving this information, Palpatine ordered Nist to gather the members of the Dark Side Elite and travel to New Alderaan to capture Skywalker and his Jedi, along with Organa Solo's children. The Dark Side Elite was then to use AT-AT walkers to destroy the New Republic settlement on the planet. The Dark Jedi squadron, known as Dark Side Squadron, boarded I-7 Howlrunner starships and departed for New Alderaan. After landing, Nist dispatched Tedryn-Sha and Krdys Mordi to poison Skywalker with scarab droids and capture him, while he and the rest of the Dark Jedi went to kidnap the Solo twins. However, Sha and Mordi failed their mission and were killed by Organa Solo and one of Skywalker's Jedi, Jem Ysanna, though Jem was mortally wounded by Sha and soon died. Meanwhile, Nist and the other Dark Jedi reached the building where the Solo children were located. After learning of Sha and Mordi's failure, Nist ordered Kvag Gthull to infiltrate the building and capture the twins.

While Gthull went to kidnap the twins, the Executor and the three remaining Dark Jedi were confronted by three of Skywalker's Jedi—Empatojayos Brand, Rayf Ysanna, and the Dark Side Elite defector Kam Solusar. After a brief lightsaber duel, one darksider was killed, and Nist himself was defeated by Solusar. Despite his defeat, the Executor quickly ordered Gthull, who had captured the twins, to command the AT-ATs to attack. Gthull followed Nist's order and alerted the AT-ATs, but the Jedi spotted him, and Organa Solo killed him with a blaster shot. With both attempts to capture the Solo twins and Skywalker having failed, Nist and the two remaining members of the Dark Side Elite took advantage of the enemies' preoccupation with the AT-AT attack and retreated to their Howlrunners.

As the New Republic troopers on New Alderaan fought against the overwhelming AT-AT forces, the smugglers who had escaped from Byss arrived, supported by an X-Wing flight group. The smugglers engaged the AT-ATs and evacuated all surviving New Republic personnel, including Skywalker, his Jedi, Organa Solo, and the twins. Xecr Nist and his Dark Jedi chased the fleeing smuggler ships in their Howlrunners, but the smugglers escaped by jumping to hyperspace.

Following the failed mission on New Alderaan, Palpatine restored the Dark Side Elite to seven members by 11 ABY and promised Nist an entire star system if he brought Skywalker's dead body to him. Meanwhile, the Emperor continued to use his Galaxy Gun, destroying targets such as the New Republic troopship Pelagia, instilling fear and forcing many planets to pledge loyalty to the Empire. During this time, Nist took possession of Bast Castle, which had belonged to Sedriss and, before him, Darth Vader. Disobeying Palpatine, Nist did not remove the statue of Vader, hoping the Emperor would forget his order. Soon, Palpatine began to suffer from the decaying effects of his clone's genetic instability, a result of treachery by the Emperor's physician, who had been bribed by Royal Guard Carnor Jax to tamper with the clones' genetic material.

Since Skywalker and the two turncoat Imperial Ruling Council members Nefta and Sa-Di had previously destroyed all other clones, and new clones could not be bred from the faulty genetic material, Palpatine needed a gene sample from a Force-sensitive to restore his clone line. To this end, Palpatine dispatched Nist to Ossus, ordering him to bring several members of the native Ysanna tribe, descended from Jedi, to Vjun. Landing on Ossus, Nist and his stormtroopers quickly secured three Ysanna shamans and herded them into Imperial hunter starships. During the loading process, one of the shamans, Okko, tried to mind trick a stormtrooper into letting him go. Sensing Okko's use of the Force, Nist punched the shaman, freeing the stormtrooper from the mind trick's effects. After capturing the shamans, Nist's forces departed Ossus, but Skywalker and his allies, who had just arrived, witnessed their departure. After tracing the Imperials to Vjun, Skywalker pursued them, aware that Nist knew he was being followed.

Landing on Vjun, Nist ordered his stormtroopers to freeze the shamans in carbonite to keep them in suspended animation until the Emperor constructed a new clone laboratory. After being informed of two approaching ships and sensing that Skywalker was aboard one, Nist ordered Bast Castle's blast doors closed but allowed the ships to land. He then assembled all six Dark Jedi and prepared to confront the Jedi at the landing pad. However, Skywalker used Solusar's robotic-controlled Howlrunner to ram the blast doors and engaged the Dark Jedi inside the castle, quickly killing two of them. As Nist and Skywalker dueled, Solusar battled three darksiders at once, while Rayf Ysanna engaged the remaining one.

After several blows, Nist and Skywalker locked their lightsabers until the Jedi suddenly deactivated his weapon. Caught off guard, Nist lost his balance and fell. Skywalker then used the Force to topple the statue of Darth Vader, crushing the three Dark Jedi who attacked Solusar. After killing the remaining darksider, the Jedi subdued Nist and took him prisoner, demanding he reveal the procedure for unfreezing the captive Ysanna shamans. Maintaining that the Emperor could not be defeated, Nist refused to tell his captors anything. Despite Nist's beliefs, the Emperor was soon killed on the planet Onderon, his spirit dragged into Chaos by Empatojayos Brand. Nist himself soon died in a New Republic prison, leaving Kam Solusar the only surviving member of the Dark Side Elite.

Xecr Nist was extremely loyal to Palpatine and advanced in submission to his will, becoming one of the reborn Palpatine's closest advisors. Nist firmly believed that his Emperor was virtually invincible and could not be killed. Fearful of his Master's authority and power, Nist usually fulfilled Palpatine's commands to the letter. The Emperor himself acknowledged Nist's loyalty before empowering him with the dark side. Such unquestionable submission eventually led Nist to possess Bast Castle, which he had long desired.

Despite his loyalty, Nist dared to disobey Palpatine's order to remove the statue of Darth Vader because of the great awe he felt toward the Emperor's former apprentice. Nist was very self-confident, believing that as the Emperor's right hand, nothing could stop him. Contrary to his beliefs, Nist was defeated in a lightsaber duel twice, first by Solusar on New Alderaan and then by Skywalker on Vjun. Nist had sadistic inclinations, considering scarab droids, which burrowed into their victims' flesh, to be "lovely creatures." The Dark Jedi had light skin and eyes that glowed yellow.

After enduring a traumatic and painful initiation into the Dark Side Elite, Xecr Nist became immersed in the dark side of the Force, adopting a more sinister attitude and manner of speech. He could wield a lightsaber in battle. The Executor trusted the dark side to guide him to Skywalker on New Alderaan and reprimanded Tedryn-Sha for failing to mask his presence from Skywalker. Nist was able to sense Okko using a mind trick on a stormtrooper and felt that Luke Skywalker was aboard one of the ships headed for Bast Castle. Although initially wary of Skywalker during the mission to New Alderaan, Nist's self-confidence grew, and he came to consider himself exceptionally powerful, ultimately concluding that Skywalker was no match for him. Despite his beliefs, all Nist's powers and lightsaber skills were insufficient to defeat the Jedi. He could pilot an I-7 Howlrunner, leading Dark Side Squadron during the mission to New Alderaan under the callsign Dark Side One.

Like all members of the Dark Side Elite, Nist wore long dark robes, heavy boots, and gauntlets, covering his head with a hood. As one of Palpatine's Dark Jedi, Nist was armed with a lightsaber.

Xecr Nist first appeared in the 1995 comic book Dark Empire II 4, written by Tom Veitch and illustrated by Cam Kennedy. The character went on to appear in the two final issues of the Star Wars: Dark Empire II series, as well as the first issue of the follow-up series Star Wars: Empire's End, illustrated by Jim Baikie, and in the audio dramatization of both comics. Nist was briefly mentioned in Sedriss's entry in The New Essential Guide to Characters, which established his death in a New Republic prison after the events of the comic book series.

There are several noticeable differences between the comic books and their audio dramatization. While the audio drama presentation of events may be canon within the Star Wars Legends continuity, for the purposes of this article, these events are described in the biography as told in the comics.

In the audio drama, Nist and Tedryn-Sha arrive aboard the Star Hauler Reliance carrying X-1 Viper droids to Byss. After reporting to Palpatine and being empowered with the dark side, they proceed to the Emperor's Citadel on Byss. Nist and Tedryn-Sha then command the planet's defense from the Citadel and contact Palpatine—who is still inspecting the Galaxy Gun—to inform him of the New Republic attack. Continuing his inspection, Palpatine dismisses Nist's predicament, leaving him to fend off the attack alone. During the battle, Tedryn-Sha is injured, and Nist orders the release of the chrysalide rancors. In the comic, both Nist and Sha are still on the shuttle with Palpatine during the battle. Additionally, in the audio version, Nist interrogates Ntthan instead of Kvag Gthull.

The most notable difference is the depiction of Nist's part in the mission to New Alderaan. In contrast to Dark Empire II, Nist does not participate in the fight between the Dark Jedi, Solusar, Rayf Ysanna, and Brand in the audio adaptation. Instead, he guards the Solo children as his darksiders fight the Jedi. After all members of the Dark Side Elite are killed, Nist tries to escape with the twins and almost reaches his ship, but Leia Organa Solo stops him with two blaster bolts. Nevertheless, Nist appears in the audio adaptation of Empire's End without any explanation of his survival. The final part of the audio drama stays closer to the source material regarding Nist's actions, with the only difference being that Nist is backed by ten Dark Jedi instead of six during the skirmish on Vjun.

Star Wars Handbook 3: Dark Empire, a guide recounting the Dark Empire comic series, also provides conflicting information. It erroneously states that Krdys Mordi underwent the initiation alongside Xecr Nist. Describing the events on New Alderaan, it only mentions Mordi and Nist, who "were both cut down." The Handbook also states that the Emperor ordered Nist to capture the Ysanna shamans to transfer his spirit into their bodies. In Empire's End, Palpatine plans to get a gene sample from the Ysanna and make new clones of himself. Finally, The New Essential Guide to Characters implies that Xecr Nist was captured on Onderon instead of Vjun.

There is also a slight inconsistency in Nist's entry in The Complete Star Wars Encyclopedia, which states that Nist was captured after Palpatine's final death on Onderon. However, in the comics, his capture occurred shortly before Palpatine's demise.