Koro Ziil

Koro Ziil was a Force-sensitive male Kel Dor from the planet Dorin, and a member of the Baran Do Sages, a Force-based organization on Dorin. As a master of the Baran Do, he trained the Sage Charsae Saal as his apprentice. In approximately 23 ABY, he took Saal—whom he had sworn to secrecy—to the Caverns of the Hidden One, a series of caves deep beneath the surface of Dorin. Ziil believed it was likely that Saal would someday join the Hidden Ones, a secret sect of the Baran Do dedicated to preserving the knowledge of the Order, so that if the sages were ever eliminated, they would have the ability to restore their Order.

Ziil went on to become Master of the Order, and was present in the Baran Do temple in Dor'shan in 34 ABY when the Jedi Knight Jacen Solo arrived on Dorin, seeking to learn various Force techniques. Ziil taught Solo several Baran Do abilities, including ayna-seff, the "dead brain" technique, which took Solo three days to master, and other techniques in the hassat-durr family—a skill set which consisted of suffusing the wielder's body with a low level of electromagnetic radiation. Ziil also trained with Solo in combat. From his time with the Jedi Knight, Ziil perceived that Solo's childhood had been unsettled, and that the Human had severed himself from it. He also found, however, that Solo seemed to be at peace with himself and the galaxy, and that his journey for knowledge was nearing its end. Several years after leaving Dorin, Solo was trained in the ways of the dark side of the Force by the Dark Lady of the Sith Lumiya. He went on to become the Sith Lord Darth Caedus, leading the Galactic Alliance in the Second Galactic Civil War.

Nine years after meeting Solo, Ziil went through the ceremony of "death"—traditional to the Baran Do who wished to join the Hidden Ones. When a Baran Do sage felt that they had done everything necessary in their life, and had nothing left for which to live but the preservation of knowledge, a ritual was performed wherein they pretended to die. After this ceremony, they would join the Hidden Ones, deep beneath the surface of Dorin. Sometime after Ziil joined the Hidden Ones, he became their leader, known as hu'aac-du'ul-staranjan—which, translated into Basic, meant "the one who dwells in darkness"—and took on the formal title of the Hidden One, no longer recognizing his old name.

Shortly after Ziil joined the Hidden Ones, Jedi Grand Master Luke Skywalker—who had been exiled from Coruscant and the Jedi Order by Chief of State Natasi Daala for failing to prevent Solo's fall to the dark side—and his son, Jedi Knight Ben Skywalker, sought out Ziil in in hopes of finding out more as to why Solo had turned to the dark side. Upon locating the Baran Do sages in Dor'shan, they learned that Ziil was dead. The Skywalkers trained with the sages, later attending Charsae Saal's funeral ceremony, when he decided to "die" as well. However, the two Jedi found a secret chamber underneath Saal's pyre, where they found the sage very much alive. They convinced the sages to allow them to travel with Saal to the Hidden Ones. Saal—who now went by the name of Chara—showed them around the caves, revealing that Ziil had taken him there nearly twenty years earlier. Chara told the Skywalkers that in order to protect the secrecy of the Hidden Ones, they would never be allowed to leave.

Ziil met with Luke and Ben and talked to them about his time with Jacen Solo, telling them of his training of the former Jedi. Changing the subject when it became clear that Ziil did not have much information on Solo's fall, Ben asked whether Ziil planned to kill the Jedi that would undoubtedly come searching for them. The Hidden One grew angry and began an argument with Ben, which finally ended when Ziil got up and walked away.

Days later, Skywalker and his son set about the task of creating permanent quarters, spending their free time exploring the caverns. The Jedi Master decided to gather all of the Hidden Ones together by announcing that he and Ben would be having their naming ceremony; however, he had no intention of actually doing so. Once they had all gathered in the throne chamber of the Hidden One, Ziil expressed his pleasure that the Skywalkers were finally choosing new names. Luke, however, revealed that when he had said they would be gathering for a naming ceremony, he meant that he was hoping to rename members of the Hidden Ones, not himself. He attempted to show the Hidden Ones that they were just wasting away down in the caverns. To Ziil's displeasure, the Jedi educated them on the nature of the Force and explained that it was the energy of life—including risk, energy, and vitality. Luke further stated that by accepting their "deaths" and joining the Hidden Ones, they had rejected these values, and were thus rejecting the Force, which was why they were weakening. As evidence, Skywalker pointed out that Ithia—who had been the best fighter in the Baran Do order before she joined the Hidden Ones—had recently lost three straight duels with Charsae Saal. Ithia had always been Saal's superior before she joined the sect, but was now weaker than the newer arrival. Ziil immediately attempted to terminate the meeting, but Skywalker continued trying to persuade the Hidden Ones that their way of life was wrong.

As the Hidden One ran out of patience, Skywalker proposed a duel between Ben and Saal—the best fighter of the Hidden Ones, and by far Ben's superior in combat. The Hidden One was annoyed by the offer, but also somewhat intrigued, and agreed to the proposal when Luke promised that if Ben lost, he and Ben would accept their fate and stay in the caverns. The combatants were each armed with a hardwood staff, and a duel ensued, with Ben emerging as the victor.

Because of this, the Hidden Ones were willing to listen to Skywalker's arguments; even Saal, Ziil's former apprentice, was ready to believe the Jedi. But Ziil did not give up so easily. He revealed that he had sent word to the surface that there had been an accidental collapse in the caves, in which the Skywalkers had been killed. Therefore, there would be no need to send down any more oxygen-nitrogen canisters, which the Skywalkers needed to breathe while in the toxic atmosphere of Dorin. Without these canisters, they would run out of air within several days and die. Several Hidden Ones spoke out in protest, which only angered Ziil further.

Ziil attacked the Jedi Master, blasting him with white Force lightning, which Luke blocked with his lightsaber. Skywalker began moving towards Ziil, who created a Force whirlwind. Luke deflected the whirlwind, and it continued around the colonnade until it hit a support column behind him, knocking it down. Ziil Force-threw his throne at Luke, which he intercepted with the fallen column. Skywalker then pushed the column along the ground towards Ziil, forcing him to jump over it. Using the distraction to his advantage, the elder Skywalker jumped up and kicked Ziil in the stomach in midair, sending him flying and ending the fight.

Even after his defeat at the hands of Skywalker, Ziil would not allow the Hidden Ones to leave. Ziil proposed that the sect would free their servants and appoint a board of advisers, and he would tell those on the surface that the earlier message reporting the deaths of the Skywalkers was a mistake. Ziil promised that after about a year, they would review the situation. Earlier, when he had been exploring the caverns, Ben had discovered a system of explosives that could be activated from any room, that when activated, would block off the only known exit from the caverns. Frustrated with Ziil's refusal to accept defeat, Ben set off the explosives with the Force. Ziil then advised that Ben had just doomed himself, because there was no other way in or out. Ben recognized that Ziil was lying, and then revealed to the Hidden Ones many of the lies that their leader had told them. Still, Ziil would not reveal the existence of a secret escape route from the caverns.

At last, a very old Kel Dor, Burra, gave in, and revealed a secret turbolift chamber. The Hidden Ones finally returned to the Baran Do on the surface. Luke later speculated that Ziil would either find a new way to continue his old goal of preserving knowledge—such as by distributing the archives of the Baran Do—or would stay down in the caverns, unable to change his ways.

Ziil proved to be a very cautious leader; he feared that the Baran Do would be purged in a similar manner as the Jedi in 19 BBY. As such, he was very set in his idea that the Hidden Ones' mission of "dying" and preserving the Baran Do's knowledge was a just and noble goal. Ziil thought nothing was more important than this way of life—the way of the Hidden Ones—and was prepared to let the Skywalkers die in order to keep the caverns secret and their Order safe from the rest of the galaxy. He also carried about him a sense of superiority. Ziil expected other beings to listen to him and obey his every word, and was thus very distressed when the Hidden Ones began turning against him.

One of the few Baran Do sages to be trained in combat, Ziil was also known to possess a wide range of Force powers, including mastery of the hassat-durr family of techniques. He was able conjure up a powerful Force whirlwind and possessed the ability to perceive buildups of energy on the planet, which could lead to dangerous weather storms. Ziil was also able to use a white version (and not inherently of the dark side) of Force lightning

Koro Ziil was created by the established Star Wars author Aaron Allston to be the leader of the Hidden Ones in Fate of the Jedi: Outcast, the first novel in the Fate of the Jedi series, released on March 24, 2009.