A Grysk male known as "Jixtus" who was at least twenty-one years old and was the coordinator of the Grysk warlike species, he led a Grysk fleet from his flagship, the Shatter-class WarMaster FateSpinner. At some point before 18 BBY, Jixtus and the Grysks trained General Yiv the Benevolent and his species, the Nikardun, in the arts of conquest in an attempt to encircle the Chiss Ascendancy, the government of the Chiss species. However, although Yiv conquered the Tower Dimension, the Paataatus Hiveborn, the Paccian Governance, and the Lioaoin Regime, he failed when conquering the Vak Combine, where he was defeated by Chiss Senior Captain Mitth'raw'nuruodo "Thrawn," which became an enemy of Jixtus. Afterward, Jixtus employed the telepathic Agbui species to cause chaos and civil wars, creating a civil war on the Unknown Regions planet Sunrise, which resulted in massive destruction, and failing in the attempt to precipitate a civil war in the Ascendancy.
With the death of Haplif, the coordinator of the Agbui, Jixtus allied himself with Generalirius Nakirre, the leader of the Kilji species' theocracy of the Kilji Illumine and its battle fleet of the Illumine Kilhorde. While the Kilhorde prevented fleeing Chiss refugees from escaping the Ascendancy, Nakirre and Jixtus traveled aboard the Kilji war cruiser Whetstone across the Chiss Ascendancy, meeting several high-ranking officials such as Clarr'ivl'exow "Rivlex," who obtained Grysk warships in exchange of information. While the families entered a battle against each other thanks to Nakirre and Jixtus' meetings sharing images of the battle between the Dasklo, Xodlak, Erighal and Pommrio families, General Crofyp and Colonel Tildnis perished while fighting Thrawn, who had previously defeated Yiv and Haplif. Thrawn, obtaining data from Tildnis' Kilji picket cruiser Hammer, allied himself with the Paataatus Hiveborn to destroy the Kilhorde, destroying the Kilhorde.
Ultimately, receiving reports from Grysks and Rivlex, Jixtus traveled to Sunrise once more, as Thrawn was present at the planet with a fleet of Chiss warships. There, he was informed of the Kilhorde's destruction, and killed Nakirre, viewing him as useless, and also fought the Chiss fleet with his own fleet, causing slight damage to the Chiss, but being defeated by Thrawn's tactics and alliance with Yiv's previously conquered people. Then, the Paccosh, Garwians, and Vaks, fought Jixtus' fleet, exacting severe casualties before Nakirre's vassals, led by Jixtus' agent, Pathfinder navigator Qilori, fired at the FateSpinner from the Whetstone, disintegrating most of the warship and forcing Jixtus to use a self-destruct mechanism to destroy his fleet before telling Thrawn that his career was over, and that the Grysks would come back and kill the Chiss, killing himself.
Jixtus, as the Grysk male called himself, was the coordinator of his species, who sought the destruction of the Chiss Ascendancy. At some point before 19 BBY, Jixtus trained the Nikardun sentient species and Nikardun General Yiv in the arts of conquest, orchestrating the Nikardun conquests across the Unknown Regions. Although the Grysk believed Yiv's conquests would fail, they still deemed them beneficial. His plan was to occupy the Chiss with the Nikardun, while the Agbui telepathic species would enter the Ascendancy and brew a civil war, and when the Chiss were fighting each other, the Grysk forces would lay siege to the Ascendancy capital of Csilla, destroying the Chiss.
At the behest of Jixtus, the Agbui Haplif, who was skilled in reading cultures and minds, orchestrated a civil war on the Unknown Regions planet Sunrise in under six months. The Agbui and the Grysks subsequently subjugated Sunrise, turning it into a mining world where they farmed nyix, a material used for warship construction. However, Haplif revealed to Jixtus that a group of two hundred refugees, led by The Magys, Sunrise's leader, escaped their planet, heading towards the Paccosh homeworld of Rapacc. As the Grysk had previously told him to "leave no witnesses," Haplif contacted a nearby Nikardun ship, telling them that the fleeing refugees planned to build an army to destroy the Nikardun Destiny. Jixtus then sent Haplif to infiltrate the Chiss Ascendancy, informing him that it would be easier now that the Chiss' attention was turned outwards towards the impending Nikardun threat.
As the Nikardun campaign unfolded, Jixtus and the Grysks watched from afar. Yiv was able to conquer the Tower Dimension, the Paataatus Hiveborn, and the Lioaoin Regime. The Nikardun also attempt to follow the Sunrise refugee ship to Rapacc, where, upon not finding them there, they would blockade and weakly attempt to subjugate the nation. In actuality, the refugees did arrive at Rapacc, but they were concealed by the Paccosh, who also lied to the Nikardun about the refugees. The Nikardun general also attempted the conquest of the Vak Combine, but he failed at the hands of Chiss Senior Captain Mitth'raw'nuruodo "Thrawn". Following Yiv's defeat, the Grysk coordinator hired Pathfinder navigator Qilori of Uandualon, an agent of Yiv, as his ship's navigator. During a voyage, Jixtus inquired the navigator on the whereabouts of Yiv. When Qilori attempted to lie, Jixtus informed him of their location deep in space, and threatened Qilori with his death in it. Qilori then informed Jixtus of Yiv's capture by Thrawn, and was informed of Jixtus' plan to destroy the Chiss. Gaining the promise of Qilori's assistance, Jixtus let the navigator continue their journey.
Soon thereafter, Jixtus would travel to the Chiss Ascendancy to check on the Agbui's progress. The Agbui Shimkif, a colleague of Haplif, would inform the Grysk of their current situation. The Agbui have manipulated a young Chiss couple, Yomie and Coduyo'po'nekri "Yoponek", into traveling with them. These Chiss, and especially Yoponek, would be immensely helpful in the Agbui's goals of learning about and infiltrating the higher echelons of the Ascendancy. Yoponek made Haplif aware of an ambitious Xodlak Councilor, Xodlak'uvi'vil "Lakuviv", and the Agbui would decide to use him in their manipulations against the Chiss. However, Lakuviv was located on Celwis, and the Agbui have promised Yomie that she would be taken to Shihon, on the other side of the Ascendancy, for the month-long Grand Migration. Haplif, unable to convince Yomie to go to Celwis, was forced to go to Shihon. Jixtus arranged a meeting with Haplif there. In this meeting, Jixtus would inform Haplif that he has three weeks to initiate contact with Lakuviv. Haplif would accept this new timetable, and Jixtus tells him that the Agbui need a new navigator for their manipulations of Lakuviv. Haplif, confused, stated that the Agbui currently employed the services of an Attendant, but Jixtus told him that he did not want the Attendant to be seen by the Chiss Ascendancy. Instead, Jixtus proposed to give Haplif a Farseeker or Void Guide, but Haplif would recommend the services of the Pathfinders. Jixtus agreed.
Many of days later, the Agbui were on route to Celwis when Haplif rendezvoused with Jixtus to pick up the new Pathfinder. After Haplif informed Jixtus that he had successfully convinced Yoponek to go Celwis and introduce him to Lakuviv, the Pathfinder, Qilori, would arrive. Jixtus informed the Pathfinder that he would be accompanying the Agbui and eventually would navigate a Chiss ship to the system of Hoxim, the location of a fake nyix mine. Qilori asked if there would be any military action, and Jixtus would tell him that any military action would take place far away from him. However, Qilori insisted that Jixtus pay consideration to which Chiss military officer he faced, reminding him of Senior Captain Thrawn's ability to personally take down General Yiv's Battle Dreadnought. Jixtus accepted Qilori's reasoning and promised to arrange for Thrawn to be occupied outside the Agbui's sphere of operation. As Haplif and Qilori depart from the meeting, Jixtus makes Qilori aware of the mystery of how the Chiss navigate through hyperspace, stating his theory that either they had their own secret navigator species or that they had some other special way of navigating through the Chaos. Jixtus also informs Qilori of legends of Lesser Space nations using computerized navigational techniques during the Chiss' involvement in a war in that region.
Upon the the Chiss' discovery of the Sunrise refugees on the Paccian Governance homeworld of Rapacc, Thrawn's ship, the Springhawk, found his way to the planet, where he, alongside the Chiss warship Grayshrike, commanded by Senior Captain Xodlak'in'daro "Lakinda", engaged in battle with one of Jixtus's Shatter-class WarMasters, the HopeBreaker. The Chiss emerged victorious in the battle, having completely destroyed the fighting capabilities of the HopeBreaker's portside. However, the HopeBreaker's companion ship, a nyix-carrying Agbui freighter, was able to escape the system without the Chiss knowing what it was. Soon thereafter, the HopeBreaker would fight another battle with the Grayshrike and Chiss Admiral Ar'alani's Vigilant above Sunrise, in which it would be completely destroyed.
As the Agbui plot continues, Qilori guided Lakuviv's senior aide, Xodlak'ji'iprip (Lakjiip), to the world of Hoxim, showing and convincing her of the authenticity of the fake Agbui nyix mine. Lakuviv, learning of the mine, was convinced to summon a family emergency to take the mine for the Xodlak family, hoping that it would bring them glory and Ruling Family Status. At the same time, the Erighal and Pommrio were succumbing to the same manipulations. However, as the three families converged on Hoxim, they are interrupted by Thrawn, who, together with the Grayshrike's temporary commander, Mid Captain Csap'ro'strob "Apros", prevented the Chiss from fighting each other and destroyed the fake nyix mine. After the Agbui's failure, Jixtus summoned Qilori for a meeting, where he thanked the Pathfinder for making him aware of Senior Captain Thrawn, promising to take him into account for his future machinations against the Chiss Ascendancy. Jixtus would also officially task Qilori with solving the mystery of how the Chiss navigate through hyperspace on their own volition.
Following Thrawn to Sunrise, Jixtus and Generalirius Nakirre arrived on the Whetstone along with Jixtus' section of the Grysk armada to prepare to attack the Chiss forces. They arrived at a scene of many apparently destroyed Chiss warships, with Jixtus, Qilori, and Nakirre concluding that the civil war had caught up to the Chiss and they had destroyed each other. After locating Thrawn as one of the last survivors, Jixtus questioned Thrawn about the Magys, to which Thrawn gave answers for providing Jixtus answered his questions. Gaining some necessary knowledge, he revealed the Kilji Illumine Kilhorde fleet has been completely destroyed. In a fit of rage, Generalirius Nakirre accosted Jixtus, but was quickly and summarily executed by Jixtus. Thrawn demanded for Jixtus's surrender, to which Jixtus refused, to which Thrawn responded by sending out a sensor ping, to alert all the supposedly destroyed Chiss ships to signal a surprise attack. The Grysk fleet was now completely out of formation and surrounded close-range by the enemy.
With Thrawn's demand for surrender, Jixtus, in regular Grysk fashion of not providing any remains for which the Chiss and especially Thrawn to study, instantly triggers explosions across the entire Grysk fleet. Only Jixtus, aboard the FateSpinner, remained. Conversely finally with Thrawn, throwing condemnation at Chiss and Thrawn alike, as well as threatening of a larger Grysk force poised to attack Thrawn after he is gone. Jixtus then triggered the same explosion device contained within the FateSpinner, killing himself.
Jixtus was the assumed name of a male Grysk enemy of the Chiss Ascendancy. He and his allies saw the Chiss as the primary obstacle to control over the Unknown Regions. He spoke in a cultured voice. While speaking with Qilori, he threatened the Pathfinder. He was seemingly darkly amused by Qilori asking if he had been General Yiv's master before claiming to have no relation to the defeated general. He was also pleased that Qilori promised to join his effort against the Chiss.
Jixtus was proficient in social manipulation and intimidation, as he coerced many Pathfinders to work for him, and forced other warlords or bureaucrats like Yiv the Benevolent and Generalirius Nakirre to be his tools without them knowing. He laid expertly laid plans, combing multiple campaigns to serve his overall goal of Chiss destruction. One instance of him doing this is using the Agbuli to stage a Chiss encounter above Hoxim, creating tension in the Syndicure while also using Kilji vessels masquerading as Chiss family vessels to stoke a civil war. He was seen as a ruthless figure by some, such as Qilori of Uandalon who worked for him mostly in fear. He was seen mostly as a strong figure and hero to those that were opponents to the Chiss.
A military mind, the being known as Jixtus suggested movements and meetings to "his associates," which were in fact slaves of the Grysks, and was able to direct and create vast military campaigns, such as his plot to destroy the Chiss Ascendancy. He was able to form alliances with head of state and government officials, such as Nakirre and Patriarch Rivlex.
Jixtus was in command of his own fleet, composed of fourteen Grysk war vessels, and his flagship, the FateSpinner. He also owned several ships. He used a shuttle to travel from the Whetstone to the FateSpinner, which could carry a hundred soldiers. While meeting Haplif, he used a ship piloted by Qilori. Wishing to keep his body a secret, Jixtus used a to conceil his identity, as well as some gloves. Inside the cloak, he carried a blaster the Grysk used to kill Nakirre.
Jixtus, the main antagonist of the Star Wars: The Ascendancy Trilogy written by Timothy Zahn, first appeared in the trilogy's first installment, Thrawn Ascendancy: Chaos Rising. The Grysk received a dynamic, Generalirius Nakirre, in the trilogy's final installment, Thrawn Ascendancy: Lesser Evil, where the generalirius slowly realizes the truth about his relationship with Jixtus. In the same novel, Jixtus foreshadows the events of Thrawn: Alliances and Thrawn: Treason, two novels of the Thrawn novel series that feature the Grysks as the main antagonists.