A Human male Jedi Master, Vannar Treece, participated in the New Sith Wars. He previously mentored Kerra Holt. During the era of the Republic Dark Age, he spearheaded several military operations in the Outer Rim Territories against Sith forces. In 1042 BBY, he commanded the ill-fated defense of Aquilaris Minor, but successfully evacuated a young Human girl who later became the Jedi Knight Kerra Holt. Later, in 1032 BBY, Treece orchestrated Operation Influx, a three-pronged Jedi strategy aimed at disrupting the production and supply of baradium, a component utilized in manufacturing munitions, within the princedom of Sith Lord Daiman. While the infiltration of Oranessan proved successful, the task force met its end at Chelloa, with the exception of Kerra Holt, who established contact with the Chelloan resistance under the leadership of former Jedi Knight Gorlan Palladane. Even after his death, Treece's principles and philosophy continued to shape his apprentice Holt, who remained committed to fighting the Sith while safeguarding innocent lives.

During the Republic Dark Age, Vannar Treece belonged to the Old Jedi Order. By the year 1042 BBY, he had risen to the rank of Jedi Knight and learned of a research endeavor at the University of Sanbra focused on discovering the Helm of Ieldis, an ancient Sith artifact. This Helm, created by Sith Lord Ieldis before the Great Hyperspace War, possessed the ability to incite sentient beings into a murderous rage. During a raid on Sanbra, Sith Lord Odion, then serving under the Sith Chagras Hegemony, uncovered information about the Ieldis research project. The research team included Aron and Mercia Holt, the parents of the future Jedi Knight Kerra Holt. He also discovered that the researchers had sought refuge on Aquilaris Minor, a planet in the Grumani sector that had previously sheltered refugees fleeing the Chagras Hegemony's onslaught.
By this point, Vannar had gained notoriety as a persistent adversary of the Sith. Using the pretext of capturing Vannar, Odion secured permission from the Calimondra family matriarch to initiate an invasion of Aquilaris Minor. Odion successfully captured the researchers, who were then forced into Project Pandemonium, a clandestine project to obtain the Helm for himself. During the conflict, Vannar oversaw the Galactic Republic's unsuccessful defense of the planet. During the subsequent Massacre of Aquilaris, he encountered a young Force-sensitive Human girl named Kerra Holt amidst the intense house-to-house combat engulfing the city of Capital Cay. Initially, Kerra Holt mistook him for an intruder and nearly fired a blaster pistol at him.
However, she quickly recognized him as a Jedi and told him how her family had told her to flee, but she went because she did not know where else to go. Feeling sympathy for her, Vannar informed Kerra about a hidden starfighter nearby and offered to help her escape offworld. He promised Kerra that they would return to Aquilaris when it was safe, and they would ensure its safety as Jedi. Holt subsequently became a Padawan under Treece's guidance. By 1032 BBY, she had successfully completed her Jedi Trials and become a novice Jedi Knight. At some point before Operation Influx, Vannar also authored the holotract Those Who Drown, which highlighted the plight of civilians in Sith-occupied space. Following his experiences on Aquilaris Minor, Vannar began leading independent "knight-errant" operations into Sith Space with a focus on the Grumani sector.
Due to the unconventional nature of these "knight errant" operations, Treece was viewed as a nonconformist by his contemporaries, at a time when the Republic's prevailing military strategy involved retreating behind a defensive perimeter in the Core Worlds and the Colonies. For these operations, Treece utilized volunteers rather than regular Jedi and Republic military personnel since Supreme Chancellor Genarra and the Ministry of Defense were hesitant to commit substantial forces and resources to invading Sith-controlled territories due to the Republic's weakened state. He also exploited a loophole that granted Jedi Knights a sixteen-day period of free travel anywhere in the galaxy between their regular routine of serving three months in law enforcement patrols and nine months of active service on the Republic's contracting frontiers. By 1032 BBY, Treece's "knight errant" operations were the only Jedi activity within the entire Grumani sector.

In that year, Treece received intelligence from former Jedi and undercover Republic operative Gorlan Palladane that Sith Lord Daiman had discovered vast deposits of baradium, a volatile compound used in the manufacture of munitions. The planet Chelloa was an exporter of baradium to the Daimanate's war forges near the frontier. Since the death of Sith Lord Chagras in 1040 BBY, the various Sith princedoms in the Grumani sector, including Chagras' nephew Daiman's Daimanate, were locked in an internecine power struggle known as the Charge Matrica. In a memorandum submitted to Chancellor Genarra, Treece recommended a strike to knock out production and to sabotage the supply lines to prevent a change in the balance of power in the region. Treece was aware of the mutual sibling rivalry between Daiman and his older brother, Sith Lord Odion. His strategy advocated keeping the Sith Lords permanently locked in stalemate to prevent one faction from dominating the entire Grumani sector.
Consequently, Treece conceived Operation Influx, a swift three-stage operation designed to disrupt the production and supply of baradium within the Daimanate. The initial stage involved infiltrating the Daimanate via the transit world of Oranessan. The second stage entailed a raid on Chelloa itself, while the third stage involved extraction by interstellar travel to neutral space. Given the gravity of Operation Influx, Vannar meticulously recruited several senior Jedi who owed him favors from the past. His team consisted of eleven Jedi, including Kerra Holt, the Quarren Master Berluk, the Trandoshan Mrssk, and the Cerean Dorvin Eltrom. Holt originally named this mission Operation Deadlock. However, it was renamed Operation Influx when Treece realized that it revealed their covert strategy of stalemating the Sith Lords against one another. This had the potential of alienating occupied civilian populations who looked up to the Jedi as their saviours and would allow the Sith to deduce the Republic's strategy.
For his former Padawan Kerra, this marked her first return to the Grumani sector since her homeworld was invaded eight years ago. Treece had learned about the baradium operations from his old friend and undercover Jedi operative Gorlan Palladane, the leader of the Chelloan resistance. Palladane and his Rodian mechanic friend Skodo had used a stolen transmitter to reactivate a hyperspace relay and communicate with Treece. However, the Sith Lord Odion had been monitoring the transmission and made preparations to invade Chelloa. The nihilistic Sith Lord believed that the planet's high concentration of baradium created an imbalance in the Force and thus had to be destroyed.
Vannar's Jedi strike team journeyed to the planet Oranessan aboard an unidentified Jedi starship. This polluted, rain-soaked world served as a crucial hyperlane hub within the Daimanate. Upon approaching Oranessan's surface, the Jedi intercepted and downed a Daimanate personnel shuttle. This shuttle was transporting flight crews to the planet's spaceport, where a fleet of Daimanate Heavy-Lift Starcrosser transports awaited departure for a delivery run to Chelloa. These flight crews were intended to operate the massive transports. The shuttle crashed on a hilltop in the mud flats, and the Jedi quickly secured the fallen crew's cloaks and identification badges. During the initial phase of Operation Influx, Treece led a four-member advance team, including Kerra and the Celegian Dorvin Eltrom, that approached the spaceport where a fleet of the Starcrosser transports were departing for Chelloa.
The four Jedi then encountered a Daimanite party consisting of a female ground crew chief and four armed sentries who attempted to execute them for being late to a flight preparation meeting that occurred twenty minutes earlier. However, the Jedi swiftly eliminated the Daimanate sentries using their lightsabers. After acquiring the dead Daimanates' equipment, the four Jedi commandeered an empty Starcrosser transport. Vannar then contacted the rest of the team via comlink to inform them that the objective vessel had been secured, that Operation Influx had been confirmed, and that they could now rejoin the advance team at the transport. During a brief conversation, his adopted daughter Kerra reflected on how she had switched from using Force Persuasion to lightsaber combat during her encounter with the ground crew chief. Kerra also admitted that she did not like posing as a Sith and Vannar responded that she could not get very far in enemy territory without employing subterfuge.
The Jedi had seized control of the Starcrosser transport and prepared to depart for Chelloa. However, the mission encountered a new obstacle when pilot Dorvin discovered that the transport's navigation computer lacked an activation cylinder, a small device that enable a ship to enter hyperspace. While it was still able to take off, the Starcrosser transport was unable to make a hyperspace jump and Operation Influx would have to be aborted. Meanwhile, the other transports were already departing for Chelloa. Kerra quickly recalled that she had forgotten to retrieve a dispatch case from the wreckage of the downed personnel shuttle they had shot down earlier. The case had been trapped under one of the shuttle's consoles and she had mistaken it for a personal item.
While it was standard procedure in the Republic for most flight crews to keep their activation cylinders with the ships, the Trandoshan Jedi Mrssk explained to his companions that the Starcrosser lacked one since Daiman had a policy requiring his flight crew to keep them on their persons in order to minimize the risk of desertion by his ground troops. When Kerra expressed frustration at her failure to retrieve the dispatch case, Treece was sympathetic towards the young Jedi woman since it was impossible for her to do everything. The Jedi were unable to travel to Chelloa on their own ship since the planet was tightly guarded by Daiman's forces. Time was running out since they had only one hour to infiltrate Chelloa and sabotage the baradium shipping before departing for neutral space.
Vannar considered activating the fallback plan which involved flying the transport back to their hidden Jedi vessel and using it to shoot down the Daimanite transports before returning to the Republic. However, this plan had a serious drawback since Daiman could respond by re-routing other vessels to Chelloa. Kerra opposed this idea and suggested hijacking an ore transport but Vannar ruled it out since the ore transports were heavily armed. Finally, Kerra suggested returning to the wrecked shuttle and retrieving the dispatch case. However, Vannar was uneasy about this plan since he did not want to risk the lives of the Jedi Knights involved. However, Kerra was still determined to carry out Operation Influx due to the considerable amount of energy, time, and resources they had already committed to the mission. At that point, they were interrupted by an announcement from the Sith control tower on Oranessan reminding them to hasten their departure or they would be punished.
Vannar then ordered the team to opt for their fallback plan. He ruled out walking back several kilometers back to their hidden Jedi ship due to the wet conditions outside. Vannar also ordered Dolvin to secure all the vessel's hatchways. However, Kerra disagreed with her master's orders and used her stolen remote control to open the transport's main cargo hatchway as it was lifting off. Donning the fallen ground crew chief's overalls, she then headed to the spaceport's hangar bay which stored several replacement navicomputers and activation cylinders. Despite flying at low altitude and the transport's external sensors, Oranessan's torrid weather made it impossible for the Jedi crew aboard the transport to detect Kerra. After several nervous minutes of waiting, Kerra returned back to the departing Starcrosser transport and used her lightsaber as a beacon.
A soaked and exhausted Kerra then climbed back onto the transport's cargo deck where she presented the activation cylinder to her pleased master. Kerra then explained how she had obtained the activation cylinder by infiltrating the hangar while disguised as a worker. Due to her stolen clothes and because she had entered during a busy period of the day, she was able to evade detection. When Treece commented that he thought that Kerra hated posing as Sith, the Jedi woman replied that she hated letting them win even more. Having obtained the activation cylinder, the Starcrosser transport was now able to make a hyperspace jump. Having successfully accomplished the first phase of Operation Influx, the relieved Treece and Kerra shared jokes prior to departing for the raid on Chelloa.

During the second phase of Operation Influx, the Jedi strike team successfully landed their stolen Starcrosser transport at Jenith's spaceport. During the raid, they rammed a squad Daimanate Sith troopers and destroyed several cargo liners to disorientate their Sith opponents. They then overwhelmed the security guards with the support of the mining workers, many of whom were members of the Chelloan resistance. During the ensuing melee, Treece cautioned his former apprentice Holt not to be reckless with her life since she had already passed the trials. He then reminded Holt of her job which was to reconnoiter with Gorlan Palladane, who was gathering a group of miners in the South Work Yard. She and Palladane's group would then rejoin the main force following the fighting.
Treece commented that Holt in the future could be the charismatic leader running the "hopeless" mission. She responded jokingly that her job was to make the charismatic leader "look good" before parting to go on her assignment. Holt saved Gorlan Palladane and his fellow miners from being killed by a T'surr Daimanate Sith officer, who wanted to kill them as part of a scorched earth strategy to ensure that no opponents could secure Daiman's labor force. She knocked out a T'surr Daimanate Sith trooper with her lightsaber while Gorlan incapacitated a human officer with his crowbar. Holt then escorted Palladane and his companions to the spaceport. By then the Sith garrison had been overpowered and Treece was being welcomed by a jubilant multi-species crowd of laborers and miners. Vannar and Gorlan reunited and shooked each others' hands as close friends. Vannar also introduced Gorlan to Kerra and introduced him as his top secret intelligence source.
Gorlan had worked as a relief worker even before the Sith occupation but had always remained in close contact with the Jedi Order. However, tensions soon developed when Gorlan noted that the small size of the Jedi taskforce was insufficient to liberate Chelloa. Vannar explained that Operation Influx was not a rescue mission but rather a preemptive strike to sabotage the distribution of baradium and prevent further incursions into the rump Republic. Gorlan criticized Vannar's "filibustering raid" as insufficient in helping ordinary people living under Sith rule. Kerra intervened and defended her Master by stressing that the Vannar was right in asserting that a small tactical raid would keep the Sith deadlocked. Vannar then took Kerra aside personally and stressed that Gorlan was right but admitted her was unable to help everyone. However, he reminded Kerra that their transport ship still had sufficient space for the dock crew. He ordered her to personally assist Gorlan in helping mobilize anyone willing to flee to Republic Space. Kerra argued that she should be assisting the other Jedi in the demolitions work since she had studied the site from orbit. Gorlan responded that her knowledge of the site's dimensions could also used be used for more peaceful work and stressed that might and mercy were part of the job.

Kerra concurred and began tending to a wounded Duros labourer. However, they were distracted by the rumble of engines emanating from Squatter's Hill. Daiman's rival and estranged brother Sith Lord Odion had arrived with an attack force comprising of landing ships and a Kinetic corruptor, a massive repulsorlift vehicle capable of harvesting baradium from the surface by igniting it. Later it was learnt that Odion had also intercepted Gorlan Palladane's transmission and learnt about Daiman's secret baradium mining operations on Chelloa. Like the Jedi, he sought to sabotage Daiman's war effort by disrupting baradium production. In the ensuing duel, Odion unleashed his Force-sensitive Novitiate acolytes on Vannar's Jedi team.
Vannar expressed surprise at Odion's presence since Chelloa was situated far from the Odionate's supply lines. Kerra also attempted to enter the fray and slay Odion in revenge for the destruction and suffering inflicted on her homeworld ten years ago. Vannar reminded Kerra of his previous order to assist Gorlan in evacuating the people and stressed that Daiman would be returning with reinforcements. He ordered her to evacuate Gorlan's people from Chelloa while emphasizing that it was his task alone to deal with Odion. Kerra returned to the freighter only to discover that Gorlan was refusing to leave because he still had a family in Jenith. Gorlan also stressed that there were still sixty thousand people in the slave cities of Chelloa and he was still needed as the de-facto leader of the Chelloan resistance. Upon learning this fact, Kerra correctly deduced that Odion was trying to destroy Aquilaris since it was too far from his supply lines to defend effectively. She told Gorlan to evacuate while she reentered the fray in an attempt to defeat Odion.
During the ensuing duel, Vannar took on Odion atop an automated repulsorlift platform with the two men goading each other. Meanwhile, the Kinetic corruptor was begin its activation process. Kerra interrupted the duel and attempted to stop the Kinetic corruptor by damaging its cables. However, she Odion stopped her and used the Force to hurl onto the repulsorlift platform where she was quickly tended to by Vannar. He ordered her to resume her original mission and sent the repulsorlift platform back to the spaceport by pressing its control button. By then, the ground had begun shaking with Odion gloating that his baradium experts had discovered how to detonate baradium. Taken by surprise, Treece was impaled by Odion from behind and all of the Jedi team with the exception of Holt were killed in the ensuing magma explosion which also killed and wounded many of Odion's cultists, Chelloan workers and Daiman's guards. Kerra was recovered by Gorlan who took her aboard the transport ship which was protected from the resulting magma flow due to its distance from the site. Vannar's death was sensed in the Force by Kerra, who became the last surviving member of the Jedi mission and was stranded on Chelloa.
Due to their strong bond, Kerra continued to look up to her fallen master. While Kerra was initially preoccupied with trying to defeat the two fraternal Sith Lords, she eventually understood and came to accept Vannar's order to save the Chelloan people. She and Gorlan subsequently organized the evacuation of the sixty thousand civilians on Chelloa. They seized control of a fleet of cargo liners and transports which became known as the Freedom Fleet. Following the Destruction of Chelloa by Daiman's kinetic corruptors, they escaped into the safety of Republic space via a hyperspace lane. Thus, Operation Influx arguably succeeded albeit belatedly.
Throughout his life, Vannar championed the plight of civilians living in Sith-occupied Space while lamenting the decline of the Republic into a rump state centered around the Core Worlds and the Colonies since it left large outlying regions lawless and occupied by hostile forces. He also decried the general tendency within the Republic to blame the victims of Sith domination for not rising up to challenge their oppressors, citing they lacked the will and the strength to defend themselves from their oppressors. However, he still argued that they could be led to overcome their condition if the "way was lit by those who fight for good." This thesis was proven right when his former apprentice Kerra almost single-handedly led the evacuation of civilians during the Great Aquilaris Deluge despite great obstacles from both her enemies and supposed allies.
Vannar also instilled a sense of selflessness and commitment among his followers, particularly his Padawan Kerra. This led non-Jedi commentators like Grace Command captain Jenn Devaad to comment that Kerra's selfless devotion to fighting for the people made her a "Vannar Treece product." Later, during her quest into the Odionate to ascertain the fate of her parents, Kerra learnt about his involvement with her late parents in a University of Sanbra research project to find the Helm of Ieldis, an ancient Sith artifact dating back to the Great Hyperspace War. She also learnt that Odion's invasion of her homeworld of Aquilaris Minor was actually motivated by a desire to acquire the Helm for himself, under the pretext of capturing Vannar who had by then become a perennial foe of the Sith.

Vannar Treece possessed innate leadership qualities, stemming from his exceptional command and persuasive speaking abilities. In addition to his leadership prowess, he was a highly competent fighter in lightsaber battles, as well as a very good instructor. Vannar projected a gentle and composed aura, which contributed to his popularity in interactions with diverse sentient beings. Nevertheless, he was also a shrewd strategist who advocated for maintaining a perpetual stalemate within Sith Space, preventing further intrusions into the diminished Galactic Republic. Furthermore, he lamented the decline of the Galactic Republic, asserting that this once-mighty civilization had deteriorated into a fragmented entity centered around a secure zone encompassing the Core Worlds and the Colonies. Despite this, Vannar passionately defended the welfare of civilian populations residing in Sith-occupied territories, dedicating himself to easing their suffering. In his written work, Those Who Drown, he criticized the common inclination within the Republic to fault the victims of Sith oppression for failing to revolt against their oppressors, arguing that they lacked the necessary resolve and strength to defend themselves and liberate themselves from the Sith warlords. However, he maintained that they could be guided to overcome their circumstances if "the path was illuminated by those who champion good." His experiences in aiding those he considered oppressed led Vannar to become a paternal figure for the young Jedi Kerra Holt after she was separated from her parents during the Massacre of Aquilaris. He cautioned her against succumbing to anger and passion, warning that it would lead to the Dark Side, and advised her to remain focused on her mission. Conversely, Vannar also contended that Jedi achieved optimal effectiveness when operating collectively and were less impactful in the broader conflict when acting independently. This viewpoint contrasted with that of fellow Jedi Gorlan Palladane, who believed that Jedi could still function effectively alone, even within enemy territory. Vannar's emphasis on adopting a strategic approach to conclude the New Sith Wars prompted Palladane to conclude that Vannar and his contemporaries were more preoccupied with engaging the Sith in combat than with the ramifications of their actions.
Similar to most Jedi, Vannar Treece was skilled in lightsaber combat and used a lightsaber with a yellow blade. Furthermore, he was a powerful leader, an accomplished orator, and possessed the knowledge to operate various spacecraft, including starfighters and cargo transports.
Vannar Treece was initially presented as a supporting character in the new Knight Errant comic series, which premiered in August of 2010 with the release of Knight Errant 0 during Celebration V. John Jackson Miller developed his backstory, Federico Dallocchio provided the artwork, and Michael Atiyeh handled the coloring. He also made an appearance in the short story Star Wars: Knight Errant: Influx, also penned by Miller, which explored the events on Oranessan leading up to the Aflame story arc. This short story was initially released on October 19, 2010. Vannar's character was killed in Knight Errant: Aflame 1, the introduction to the Star Wars: Knight Errant: Aflame story arc, which was first published on October 13, 2010. However, he continues to make occasional cameo appearances in recurring flashback sequences throughout the series and is still referenced throughout the series.