Antinnis Tremayne, a cyborg male Human, served the Imperial forces as a High Inquisitor during the Galactic Civil War. Initially trained as a Padawan under Master Dav Kylanu, Tremayne became an agent of Darth Vader. The Clone Wars saw the death of his master and Tremayne's capture by enemy forces, sidelining him for the remainder of the conflict. With the rise of the New Order, he avoided both Order 66 and the Great Jedi Purge. Instead, he was transported along with other Jedi trainees to Byss, where Vader recruited him as a founding member of the Inquisitorius, a novel division within Imperial Intelligence.
Rapidly embracing the dark side of the Force, Tremayne dedicated himself to the pursuit of fugitive Jedi who posed a threat to the Empire. His obsession with his targets was intense, as demonstrated by his months-long hunt for "Jodd Sonta," who was in reality the Jedi Padawan Drake Lo'gaan. Despite failing to capture or eliminate Lo'gaan, he was assigned other duties, including locating and converting fugitive Jedi on distant planets. He successfully converted many to the Inquisitorius's cause and developed exceptional interrogation skills. Tremayne's interrogation abilities became unmatched, making him a frequent choice for COMPNOR and Imperial Intelligence when dealing with resistant individuals.
As Tremayne's reputation grew, fear of him spread among both allies and enemies. He became fixated on another Jedi, Corwin Shelvay, a pursuit that cost Tremayne an eye and an arm. However, he managed to kill Jedi Master Darrin Arkanian, which further bolstered his confidence. He was then placed in command of the Interrogator, using it to eradicate Rebel cells and pursue rebellious Dark Side Adepts. Following the Empire's collapse, Tremayne chose to align with Hethrir, another former student of Vader. Nevertheless, the Procurator of Justice's splinter movement was swiftly crushed by the New Republic.
At only nineteen months old, Antinnis Tremayne was entrusted to the Jedi Order for training as a Jedi Knight. Unlike other Jedi, he maintained contact with his mother. At fifteen, Jedi Master Dav Kylanu selected him as his apprentice. After three years as Kylanu's Padawan, Tremayne was reprimanded for his vanity, and Kylanu taught him the importance of truth to the Jedi. Despite Kylanu's influence, Tremayne's fascination with the dark side of the Force grew, causing concern within the Order. Despite this, Tremayne participated in the Clone Wars, but the conflict's brutality deeply affected him. During one mission, the Confederacy of Independent Systems killed Kylanu, and Tremayne was captured and imprisoned until 19 BBY.

The Declaration of a New Order and Order 66 led to the Jedi Order's virtual annihilation, forcing the survivors into hiding. Tremayne was among those captured by Palpatine's agents and taken to the Deep Core world of Byss. Under Sly Moore's supervision, he was held with other captured Padawans and Agricultural Corps members. During an inspection tour, Darth Vader, the new Dark Lord of the Sith, was instructed by Palpatine to select worthy candidates to form a Jedi-hunting team, the Inquisitorius. Palpatine ordered the prisoners' cuffs deactivated and provided them with staffs to attack Vader.
Vader, unarmed, easily defended himself against the Padawans, mocking their lack of skill. As Vader choked two prisoners, Tremayne noticed an opportunity: Vader's chest panel, which regulated his artificial breathing. He pressed a button on the panel, causing Vader to release the prisoners and gasp for air. Impressed, Vader chose four potential pupils: Tremayne, Gwellib Ap-Llewff, Lanu Pasiq, and Halmere, while the remaining Padawans and AgriCorps members were executed. Now working for the Empire as Vader's apprentice, Tremayne succumbed to the dark side of the Force.

One of Tremayne's initial tasks involved delivering a speech in the Jrade District on Coruscant, addressing the Commission for the Preservation of the New Order's Sub-Adult Group. He praised Palpatine's policies, hinted at the upcoming Human supremacy in the galaxy, discussed advancement in the New Order, and offered COMPNOR membership to the teenage audience, exempting them from curfew. Tremayne also offered paid jobs. After his speech, he had Halmere gather the names of all attendees, sensing a Jedi presence.
Following the recruitment drive, Tremayne sparred with his fellow Inquisitors. As Vader watched, Tremayne informed his master of the Jedi presence and rumors of a rogue Padawan in the lower levels. During the duel, Vader criticized Tremayne's defensive stance and ordered him to attack. After Tremayne gained the upper hand over his fellow Inquisitors, Vader ordered him to hunt down and eliminate the Jedi.
Using Halmere's data, they identified three people from the Jrade district drive with questionable backgrounds: Ash Lynn, Jodd Sonta, and Bray Kopedon. Tremayne focused on Sonta and dispatched stormtroopers to detain the suspected Jedi at Platform DN6-4435. However, Sonta escaped. Tremayne deduced that Sonta was interested in the transport departing from DN6-4435 for Byss. Forty minutes before departure, he surrounded the ship with troops and boarded it himself, anticipating Sonta's arrival. The ship was a slave ship, filled with non-Humans destined to build Palpatine's citadel on Byss.
Sonta, disguised, infiltrated the ship, and Tremayne encountered him in the corridors. Sonta was searching for his friend and fellow Padawan, Zonder, a Selonian among the slaves. Tremayne revealed Zonder's location during a taunt, and Sonta's ally, Ekria, used the information to find Zonder. Meanwhile, Tremayne and Sonta fought, and the Inquisitor offered the Jedi a place in his organization. The Jedi refused, and they engaged in a lightsabers duel. After a brief fight, Sonta kicked Tremayne in the face, disarming him. Enraged, Tremayne ordered Zonder's death, while Sonta restrained him.
As Sonta fled, Tremayne escaped his restraints and ordered his troops to fire on the resisting aliens, who had overwhelmed the other Inquisitors. He also ordered the ship to depart immediately. Sonta and his allies escaped, but the Jedi returned to warn Onnelly Praji, a young girl on the transport, about the ship's destination. Tremayne caught him and tried to arrest him, but Sonta escaped again, cutting open a window and jumping into Imperial City. Frustrated and humiliated, Tremayne ordered his fellow Inquisitors to conceal his failure from Vader and vowed to capture the Padawans before Vader's return.

Later, Tremayne was sent to a remote world to hunt two Jedi, a Zeltron and a Gotal. He couldn't capture them alive, as the Gotal sacrificed himself to protect his village, and the Zeltron died during interrogation. However, he learned the location of other Jedi, such as Niebur Boton. He had difficulty working with Imperial Intelligence Director Armand Isard. Upon returning to Coruscant, he voiced his concerns to Darth Vader, who promised to speak with Isard. Tremayne then questioned Inquisitor Pasiq about Sonta's whereabouts, but she had no new information.
The next day, at Imperial Intelligence Headquarters, the Inquisitors searched for Sonta by examining camera feeds and civilian media. Isard approached Tremayne, complaining that the Inquisitorius's broad parameters were consuming significant Intelligence resources. As Tremayne and Isard argued, Inquisitor Pasiq found a news report about a pair of Omwati who had been attacked the previous night and rescued by three individuals with superhuman abilities. Convinced that the perpetrators were Sonta and his allies, Tremayne planned a trap.
He sent probes to the Omwati residence, unaware of Boushh, a Black Sun bounty hunter tasked with eliminating Kodo Finn. As expected, Sonta arrived, and Tremayne's stormtroopers stormed in, capturing the bounty hunter and the Jedi. As Tremayne entered, Sonta fled, jumping out a window as he had done before. Thwarted again, Tremayne returned to his quarters to meditate.
During meditation, he saw Prince Xizor flirting with Inquisitor Pasiq. Xizor introduced himself and revealed details about Tremayne's past, including his first name, which Tremayne himself barely remembered. Xizor revealed his awareness of Tremayne's hunt for Sonta and the fact that Tremayne had concealed his failure from Vader. Effectively blackmailing him, Xizor demanded information on the Dark Lord.

Subsequently, Tremayne was summoned to Xizor's residence, where the Falleen Prince offered him a gift in exchange for a holographic recording of a meeting between Orman Tagge and Palpatine to Vader. Tremayne tentatively agreed, and Xizor revealed his gift: the fugitive Padawan Zonder, one of Sonta's accomplices. Back at the Inquisitorius headquarters, Tremayne, with Pasiq's help, began brutally interrogating and torturing Zonder. The Selonian resisted fiercely, attracting Lord Vader's attention.
Vader released the Selonian, gave him his lightsaber, and activated his communication device, transmitting a hologram to Sonta and Ekria. Tremayne watched as Vader dueled with Zonder, severely injuring him before decapitating him. Vader knew this would lure the accomplices out of hiding, seeking revenge. The Dark Lord then turned on his apprentice, demanding to know why he had kept the fugitive Jedi a secret. He throttled Tremayne before viewing the Tagge/Palpatine holorecording. Following this, he told Tremayne that the Inquisitorius would receive extra help in apprehending Sonta. Vader also revealed Sonta's real name: Drake Lo'gaan.
Help came in the form of Armand Isard and clone Commander Bly, whom the Padawans had evaded on Felucia when Order 66 occurred. Bly provided knowledge about Ekria, a skilled slicer. Isard adjusted his tracking tactics, and the Imperials soon located Lo'gaan's hideout. Taking a Low Altitude Assault Transport to the location, they found it destroyed by explosives. Pasiq speculated that the Padawans had died in the explosion, but Tremayne detected them leaving in an airspeeder.
A dangerous chase ensued through Imperial City, and though Ekria jumped off the speeder, Tremayne ordered Bly to continue chasing Lo'gaan. They eventually reached Platform NL1922, where Lord Vader was scheduled to depart for Tepasi. Lo'gaan attempted to attack Vader, but the Dark Lord's Noghri bodyguards apprehended him. Tremayne apologized for his failure, but Vader was indifferent, ordering the Inquisitor to find the girl. He failed, and Ekria made her own way to Tepasi. There, both she and Lo'gaan were presumed dead.
Tremayne, along with fellow Inquisitor Ameesa Darys, was recruited by Grand Inquisitor Laddinare Torbin to help capture Arden Lyn. Lyn was an ancient woman, preserved for over twenty-five thousand years. A master of Teräs Käsi, she proved more than a match for the two junior Inquisitors. Darys died during the fight, and Tremayne suffered severe injuries. When Torbin stopped the fight by severing Lyn's arm, Tremayne moved in for the kill, but the Grand Inquisitor decided Palpatine might have a use for the ancient warrior. Tremayne, however, would not forget Lyn and the damage she caused him.
Tremayne was eventually promoted to High Inquisitor, rumored to be one of the Emperor's Hands. He was only accountable to Grand Inquisitors, Palpatine's most respected advisors, Palpatine himself, and his master, Darth Vader. Since his loss to Lo'gaan on the slave ship, Tremayne had honed his lightsaber skills to what he considered perfection. Feared in the Outer Rim Territories, he gained a reputation as a master torturer. However, Imperial Intelligence was generally skilled at interrogation, so Tremayne focused on finding potential Dark Side Adepts. He found them in isolated communities, as village shamans and dark side devotees. Tremayne also readily recruited alien Force-sensitives to his cause. His repeated successes led him to believe he would one day become Grand Inquisitor.
While some Jedi were incorruptible, others could be swayed to the Emperor's will. One such candidate was Jerec, a Miralukan Jedi Master who had taken a sabbatical to the Unknown Regions during the Clone Wars, searching for ancient Jedi artifacts. Tremayne found him there and offered him a place in the Inquisitorius, claiming it would ensure his survival under Palpatine's New Order, rather than killing him. Jerec valued his life over Jedi ideals and accepted Tremayne's offer. Another of Tremayne's discoveries was the Firrerreo Hethrir and his mate Rillao. Upon finding them, he tortured them, hoping to learn the location of Jedi fugitives. However, they were not Jedi and had no connection to them. Believing they would make suitable Dark Side Adepts, Tremayne took them to his master for training. In time, he developed a rivalry with Hethrir.

Several years after the failed hunt for Lo'gaan, before 10 BBY, Tremayne became obsessed with Corwin Shelvay, known to associate with those resisting the New Order. Before confronting Shelvay, he murdered the Jedi's parents and forced his sister, Elena, to join COMPNOR. After Shelvay was captured, he underwent COMPNOR and Intelligence interrogations before being transferred to Tremayne. By this time, Tremayne had broken every prisoner he had captured, but Shelvay resisted brutal torture for two weeks. Before Tremayne could continue the interrogation, Shelvay's master, Darrin Arkanian, rescued Shelvay and escaped, planning to leave Imperial Center with Captain Rashh.
Upon learning of Shelvay's escape, Tremayne gathered a squad of troops and pursued the fugitives. Shelvay's injuries from the torture forced his master to carry him, slowing their progress. Tremayne caught up with them in a courtyard near their departure point and revealed himself. Arkanian confronted Tremayne, but Shelvay weakened and collapsed. Tremayne seized the opportunity and attacked Arkanian with his green lightsaber. A fierce duel ensued, with Tremayne mocking the Sullustan Jedi, and Arkanian retaliating.
Tremayne's troopers appeared, and Tremayne threatened to kill Shelvay if Arkanian didn't surrender. The Sullustan relented and deactivated his lightsaber, hoping Tremayne would free Shelvay. However, Tremayne dissected the Jedi Master before Shelvay's eyes. Tremayne gloated over Arkanian's corpse, as it was the first Jedi Master he had ever killed. Shelvay's reaction was violent. Touching the dark side of the Force, the young Padawan took up his master's blade and attacked Tremayne with vengeance. The High Inquisitor struggled to defend himself and didn't anticipate Shelvay's unorthodox attack. As a result, he lost his arm and eye on the right side of his body to the young Jedi's blade.
Tremayne awoke in a medical ward with a new prosthetic arm and eye. The droids revealed that Lord Vader had chosen cumbersome and unattractive prosthetics to curb the Inquisitor's ego. Enraged at being defeated by a Padawan, Vader chastised Tremayne for his failure. His only consolation was Arkanian's death, and Tremayne vowed to find and break Shelvay. For the time being, he was content knowing his dark side knowledge would increase by their next meeting. He would also use the cumbersome cybernetics to instill fear in onlookers. With the rise of the Alliance to Restore the Republic and Shelvay's ties to them, Tremayne resumed his hunt, using the Star Destroyer Inquisitor.

Before the Battle of Yavin occurred, the Inquisitor Tremayne encountered a Force-sensitive slave known as Leesub Sirln. This Qiraash individual, Sirln, was chosen by the Inquisitor to become a Force Adept within the Empire's ranks. Nevertheless, Sirln managed to escape from Tremayne's grasp, finding refuge on Tatooine, thus leaving the Inquisitor without his intended recruit. After the Battle of Yavin, Tremayne was placed in command of the Imperial II-class Star Destroyer called the Interrogator. Furthermore, he found himself in the position of owing a life debt to the Srrors'tok warrior Ahnjai Rahmma, who served as the High Inquisitor's personal bodyguard. Despite Rahmma's deep-seated dislike for both Tremayne and the Empire, his culture compelled him to honor the life debt until either his own demise or Tremayne's. Tremayne, in return, subjected Rahmma to demeaning treatment, ridiculing him in the presence of others and assigning him perilous assassination missions. During this period, Tremayne was recognized by both allies and adversaries as one of the most formidable Inquisitors in active service.
During the war, Tremayne conceived a novel set of detention authorizations, formally known as Legal Authorization for Advanced Confinement Documents, but commonly referred to as "LAACDocs." These documents granted Imperial personnel the authority to employ any means necessary to apprehend prisoners sought by the High Inquisitors. The use of a LAACDoc required no substantiating evidence or proof, and Moffs, Generals, and even Prefects could detain individuals at their discretion until an Inquisitor arrived for interrogation. While Vader endorsed Tremayne's initiative, the LAACDocs quickly became a source of resentment among those tasked with completing them.
Although Tremayne frequently criticized his superior's strategies and modus operandi, he emulated Vader's leadership approach. Aboard the Interrogator, he displayed zero tolerance for failure or tardiness, executing officers who failed to meet his exacting standards. Following the execution of Captain Nolaan, he systematically eliminated all those perceived to be Nolaan's friends, with the exception of Jovan Vharing. Vharing assumed the role of captain, but during an expedition through the region of space known as the Nharqis'I, a critical error in judgment transpired. Lieutenant Leeds, mistakenly believing he had intercepted a Rebel transmission while Vharing was asleep, dispatched TIE Bombers from the Interrogator to obliterate the perceived source located on Qlothos.

However, the atmospheric conditions of Qlothos interfered with the TIE Bombers' missiles, resulting in the deaths of over sixty Imperial citizens on the planet's surface. Upon learning of this catastrophe, Tremayne summoned Captain Vharing to his designated "interview" chamber. He deliberately made Vharing wait outside the room for an extended period, amplifying the captain's apprehension. After a three-hour delay, Tremayne opened the door and swiftly snapped Vharing's neck, killing him and using his demise as a cautionary example to other officers deemed incompetent.
Years later, Grand Admiral Demetrius Zaarin launched a coup d'etat, abducting Emperor Palpatine from Imperial Center with the assistance of former Emperor's Hand Arden Lyn. Tremayne collaborated with Lord Vader and Maarek Stele to thwart the attempt. While Grand Admiral Thrawn was assigned the task of pursuing Zaarin, Tremayne was tasked with locating Lyn. Despite harboring resentment over a previous defeat at Lyn's hands, the Inquisitor was unable to capture or eliminate her.
When fellow Inquisitor Adalric Brandl defected from the Empire, Tremayne was ordered to apprehend him. He managed to intercept Brandl, inflicting a wound on the fugitive's hand, but Brandl retaliated, forcing Tremayne to retreat and allowing Brandl to escape to Najiba. Shortly thereafter, Brandl was captured by Admiral Etnam's flagship. Etnam contacted Tremayne, who eagerly anticipated "interviewing" Brandl, fueled by anger over his failure to prevent the traitor's escape and seeking retribution for what he perceived as a blemish on his reputation. The High Inquisitor swiftly arrived in the Interrogator to rendezvous with the Admiral. However, Brandl deceived Etnam and staged his own death before Tremayne could arrive.
Following the Emperor's initial demise at Endor in 4 ABY, Hethrir, now the Procurator of Justice, established the Empire Reborn. As the Procurator enlisted influential allies into his splinter faction amidst the power vacuum created by Palpatine's absence, Tremayne deemed it advantageous to support his former rival's endeavors. He forged an alliance with Hethrir, while maintaining secrecy regarding his involvement with the organization. In 12 ABY, he divulged the existence of the Valley of the Jedi to the Procurator. Intrigued, Hethrir assigned his other ally, Desann, to locate and exploit the valley. However, Desann's efforts were thwarted by New Republic agent Kyle Katarn.
A consistent source of reprimand for Tremayne, from both of his superiors, was his inherent vanity. Master Kylanu found it abhorrent and attempted to suppress it, albeit unsuccessfully. Lord Vader, conversely, adopted a more forceful approach, resorting to violence whenever Tremayne exhibited excessive arrogance. Tremayne's vanity would ultimately prove to be his undoing during his confrontation with Shelvay on Imperial Center, as his overconfidence led him to believe he could effortlessly anticipate the Padawan's combat maneuvers. As a consequence of this misjudgment, he lost an arm and an eye, prompting Vader to personally select cumbersome replacements as a constant reminder of his vanity and overconfidence. Conversely, Tremayne's fervor occasionally served him well, as it played a role in his initial acceptance into the Inquisitorius.

Tremayne was prone to developing obsessions, initially exemplified by his pursuit of Drake Lo'gaan. He relentlessly pursued Lo'gaan, a significantly younger individual, for several months, even prioritizing this pursuit over opportunities to locate other Jedi fugitives on distant worlds. His emotional entanglement in the case eventually displeased his master. Furthermore, he attempted to conceal his pursuit from Vader, but to no avail. When the prospect of capturing fugitive Jedi Corwin Shelvay arose, Tremayne once again became consumed by obsession, going so far as to execute Shelvay's parents and capture his sister. When Shelvay proved to be one of the few individuals capable of resisting Tremayne's "interview" techniques and escaped Imperial Center, Tremayne initially found satisfaction in the prospect of Shelvay's growth in the Force before their next encounter, but he ultimately dedicated himself to locating the fugitive Jedi.
Tremayne harbored a deep aversion to failure and was quick to punish it. During his command of the Interrogator, he cycled through commanders at an alarming rate, executing officers for even the slightest misstep, occasionally even executing the wrong individual. He would even execute those known to have associated with the offending officer, leading to mass courts-martial and subsequent mass promotions. Whenever Tremayne himself failed, he invariably sought to conceal it from his master and readily shifted blame onto others. Vader, in turn, would punish Tremayne for his failures, instilling in the Inquisitor a greater sense of mindfulness in the future.
However, a streak of cowardice permeated Tremayne's character: he callously struck down the unarmed Master Arkanian, ordered the execution of innocent members of the Shelvay family for no other reason than to reach Corwin Shelvay, directed troops to fire upon unarmed slaves, and even formulated doctrines that permitted the arbitrary arrest of innocent citizens. He frequently employed unarmed and innocent individuals as bait in traps and summarily executed officers through slow, agonizing asphyxiation.
The High Inquisitor held a firm belief in the Empire he served and occasionally expressed his patriotic sentiments. He viewed the Death Stars as embodying the most potent aspects of Palpatine's policies and believed that the destruction of Alderaan was offset by the destruction of both superweapons.
Despite his flaws, Tremayne was regarded as a handsome individual with a polite and courteous demeanor. His victims, when given the opportunity, perceived him as a "friend," which aided Tremayne in extracting information from them. He utilized the cumbersome cybernetics chosen for him by Vader to instill fear in his adversaries and often employed his booming voice to great effect. Despite this, he typically maintained a calm and soft-spoken demeanor.
Tremayne's skill in hunting and interrogation fueled his aspirations. He harbored hopes of eventually being promoted to Grand Inquisitor.
Initially, Tremayne's greatest asset was his ability to capitalize on opportunities, rather than his inherent Force abilities. While he could defeat his fellow Inquisitors in combat, he struggled against Drake Lo'gaan on the Byss-bound slave ship. He also suffered a humiliating defeat at the hands of Arden Lyn. Over the ensuing years, Tremayne honed his lightsaber skills, eventually considering himself highly proficient. His skills served him well against Darrin Arkanian, engaging him in a stalemate before resorting to a distraction to land a lethal blow, but once again failed him when dueling Corwin Shelvay, who caught him off guard during his gloating. Tremayne's arrogance at this moment cost him his right arm and right eye. He wielded a green lightsaber during his tenure as an Inquisitor. Whether this was also his lightsaber during his time as a Jedi remains unknown.

Tremayne's most valuable skill was his ability to extract information from prisoners. While Imperial Intelligence and COMPNOR were generally capable of handling prisoners themselves, they occasionally turned over particularly challenging individuals to the Inquisitorius, and specifically to Tremayne. Departing from his master's more direct and brutal interrogation methods, Tremayne adopted a subtle approach, often probing his victims' minds before commencing interrogation. He would then assume the role of the victim's "friend," engaging them in casual conversation to loosen their tongues and extract the desired information. If that failed, he would resort to more "persuasive" methods, which typically resulted in the subject's death or severe injury. Tremayne's skills were infamous, and few could resist him.
Tremayne was also adept at converting potential adepts to the cause of the Inquisitorius, and while he did not always succeed, his successes outweighed his failures. He could locate Force-sensitives in the most obscure locations, even recruiting Jerec from the Unknown Regions. He never missed an opportunity to convert someone and always made joining the Inquisitorius appear to be an appealing option to the subject. However, he frequently resorted to violence.
Although Tremayne generally favored a more reasonable, persuasive, and friendly approach, he demonstrated proficiency with the Force on the rare occasions he utilized it. He occasionally employed Telekinesis. Notable displays of his telekinetic abilities included using Force Push on Gwellib Ap-Llewff during training with his fellow Inquisitors to maintain focus on Lanu Pasiq, and then subsequently using Force Push on Lanu a few moments later. He then showcased an impressive display of the Force by disarming all of his fellow Inquisitors, summoning their lightsabers to him. Shortly before his battle with Drake, he used Force Push on him before attempting persuasion, and then during their duel. A year later, while still hunting Drake, he accurately sensed Drake's presence on Coruscant, even without knowing his precise location. He later Force Choked and ultimately broke Jovan Vharing's neck, both for his connections to Nolaan and for failing to prevent the attack on the source of transmission codes on Qlosthos. In his final moments, Jovan experienced a vision of the future, although it remains uncertain whether this vision was projected into his mind by Tremayne.
Tremayne possessed the ability to speak the Sith language.

The character of High Inquisitor Tremayne was conceived in 1993 by Simon Smith and Eric S. Trautmann as a non-player character (NPC) villain in Star Wars: The Roleplaying Game. He made his debut in the supplement book Galaxy Guide 9: Fragments from the Rim and was mentioned in passing in the subsequent book Galaxy Guide 10: Bounty Hunters. In 1995, during the initial planning stages for The DarkStryder Campaign, Tremayne was considered for inclusion as an antagonist in the series. However, his inclusion was ultimately scrapped because the character of Kaiya Adrimetrum, the main protagonist and captain of the New Republic vessel FarStar, had made her first appearance in the same book as Tremayne—Galaxy Guide 9: Fragments from the Rim. This information was later revealed in a "Behind-the-scenes" section in 1996's Endgame, the concluding book of the DarkStryder series. The character's first full appearance occurred in 1996, when he was used as a central character in Patricia A. Jackson's Star Wars Adventure Journal short story, The Longest Fall. Later that same year, a scenario mentioned in Galaxy Guide 9 was expanded upon by Eric S. Trautmann in Dark Vendetta.
Dark Vendetta featured Tremayne as the protagonist and provided elements of a backstory for the High Inquisitor. It also presented a physical portrayal of Tremayne that contradicted his description in Galaxy Guide 9 as a "slender Human." With the release of the prequels in 1999, the details of Tremayne's past suddenly clashed with elements introduced by George Lucas in Star Wars: Episode I The Phantom Menace, such as the timeline of Palpatine's ascension to Emperor, the Great Jedi Purge, and Anakin Skywalker's transformation into Darth Vader. Dark Vendetta asserted that Palpatine had ascended to the position of Emperor while the Jedi Order was still active and that "Darth Vader" was also in existence at this time. However, Star Wars: Episode III Revenge of the Sith revealed that the destruction of the Jedi Order coincided with Palpatine's ascension. These discrepancies were reconciled by Paul Ens, who utilized Tremayne as the primary antagonist in his 2005-2006 webstrip series, Evasive Action. Ens also bestowed upon the character the first name of "Antinnis." Despite these reconciliations, several statements in Dark Vendetta still conflict with Evasive Action: Recruitment. Dark Vendetta depicted Tremayne experiencing a flashback in which Vader gradually recruits him to the cause of the Empire, whereas Recruitment portrayed the conversion as almost immediate. Furthermore, the backstory dates established for Tremayne in Dark Vendetta were retconned in Evasive Action: Prey. In Dark Vendetta, Tremayne's Force-Sensitivity was said to be discovered shortly after his fifteenth birthday by a quiet, bearded man, causing his mother to cry with pleasure and pride. However, with the release of Star Wars: Episode I The Phantom Menace, it was established that Jedi were taken from their parents at a very young age, before they could form attachments to their family. To align this with the newly established lore, Evasive Action: Prey decided to establish that Tremayne was handed over to the Jedi at the age of nineteen months. However, it is important to note that this information was provided by Xizor, along with a plethora of other details, such as his first name, the death of his master, and his capture by the CIS. Therefore, it is possible that Xizor's information contains inaccuracies, although there is no evidence to confirm or deny his knowledge of Tremayne. However, Xizor somehow discovered that Tremayne was keeping his mission a secret from Vader, which lends some credibility to his information. It should be noted that Xizor was with Lanu Pasiq shortly before meeting Tremayne, suggesting that she may have leaked information about Tremayne hiding his mission from Vader to him. However, this remains unconfirmed.
Tremayne was also referenced in Emanations of Darkness, another short story by Jackson, which, due to the cancellation of Adventure Journal, has not been canonically published.
Following the incident over Trulalis, Brandl surrendered himself to the Empire after a failed attempt to train Fable Astin. However, instead of presenting Astin to the Emperor as a gift, he offered his son instead. Jaalib Brandl was handed over to Tremayne for instruction, which angered Brandl. The former Jedi harbored animosity towards Tremayne, and the High Inquisitor reciprocated those feelings. Tremayne channeled his hatred of Brandl towards Jaalib in various ways, and although the High Inquisitor never fully converted Jaalib to the dark side, the young Jedi would eventually fall several years later.