Wullf Yularen

"It is said that no traitor escapes the eye of Yularen for long."

- Lieutenant Yogar Lyste

Wullf Yularen was a male human who served as a high-ranking officer in both the Galactic Republic and its successor state, the Galactic Empire. Serving the Republic during the Battle of Malastare Narrows, he was given an admiral's commission in the Republic Navy following the outbreak of the Clone Wars, assigned to Jedi General Anakin Skywalker. Yularen overcame an initially-rocky relationship with his Jedi superior to successfully combat the Confederacy of Independent Systems in several battles throughout the conflict, including Christophsis, the Kaliida Nebula, and Geonosis. Narrowly escaping the destruction of his flagship, the Resolute, by 20 BBY he was considered one of the preeminent naval officers of the time.

With the Republic's transition into the Galactic Empire, Yularen resigned his commission in favor of becoming a colonel in the Imperial Security Bureau, and in this capacity rooted out sedition in the Imperial Senate as well as served as a liason to the Naval Intelligence Agency. Following the events of the Berch Teller campaign, Yularen was eventually promoted to head the reformed NIA, with the rank of Deputy Director. However, he continued playing an important role in the ISB, and became an early ally of the Chiss Thrawn as he rose through the ranks of the Imperial Navy, assisting him in his campaigns against the rebel agent Nevil Cygni.

In response to the growing rebellion, Colonel Yularen assisted now-Grand Admiral Thrawn in hunting for the rebel mole Fulcrum, who leaked Imperial intelligence to the rebels. Working with Thrawn, Yularen discovered that the rebel mole was his former student Agent Alexsandr Kallus. Following the Battle of Scarif, Yularen was one of the officers assigned to the Death Star battle station, where he would be killed during the Battle of Yavin.

Early Career
"He tore our ships apart. We barely escaped with our lives. In the end, a Jedi-led task force moved in to settle the matter. Trench's ship was destroyed, and we assumed he went down with it."

- Wullf Yularen, on Trench and the Battle of Malastare Narrows

Wullf Yularen was a human male born on the planet Coruscant. Prior to the start of the Clone Wars, Yularen served as an officer in the Republic Navy. He participated in the Battle of Malastare Narrows, a conflict in which a fleet organized by the Corporate Alliance blockaded the planet Malastare. Despite his best efforts, the enemy fleet, led by the brilliant Harch tactician Admiral Trench, proved impossible to break, and Yularen lost many of his own forces. Eventually, a dispatched Jedi task force turned the tide of the battle, defeating the Corporate fleet, vaporizing Trench's flagship, and seemingly killing him in the process. Despite the victory, Yularen left the battle with a lasting fear of the Admiral's tactical capabilities. He served in the Republic Senate Bureau of Intelligence for a time, until he retired.

The Clone Wars
"Of all the Jedi, why did I have to end up with Skywalker?"

- Wullf Yularen, on his assignment to Anakin Skywalker's fleet during the Clone Wars

Following the eruption of the Clone Wars in 22 BBY and the formation of the Grand Army of the Republic, Supreme Chancellor Sheev Palpatine encouraged Yularen to join the brand new Republic Navy, awarding him the rank of Admiral, making him the youngest member of the naval corps to achieve this rank. Since a war bargain struck between the Jedi Order and Chancellor ensured that the new Jedi Generals would be paired with veteran naval officers, Admiral Yularen was assigned to Jedi Knight Anakin Skywalker. Initially in command of a Venator-class Star Destroyer, this starship heavily damaged in the Battle of Teth, after which he would be posted to the cruiser Resolute, the flagship of General Skywalker.

Christophsis and Teth
During the Battle of Christophsis, Yularen initially failed to break through the Separatist blockade of the planet with supplies for Senator Bail Organa's force trapped on the planet. Recognizing his insignia on the Separatist flagship, the dreadnought Invincible, Yularen concluded that Trench had survived at Malastare and was facing him once again. Fearing his capabilities, Yularen regrouped on the far side of Leesis, Christophsis' moon. Reinforced by Jedi Master Obi-Wan Kenobi's Negotiator, Yularen personally participated in a mercy mission aboard a new model of stealth ship to provide relief to the planet below.

The ship, fitted with an experimental cloaking device, easily slipped past the blockade. However, Trench, emboldened by the lull in the fighting, ordered a flight of Hyena bombers to attack Organa's position on the planet's surface in an attempt to draw out the Republic force and destroy it. Despite Kenobi's preparations, Yularen recognized that any counterattack would result in heavy casualties for their fleet. The Jedi, Skywalker, was able to outmaneuver Trench's attacks and destroy the Invincible. Despite his initial skepticism and friction with the Jedi, the Admiral was impressed with Skywalker's unorthodoxy, who commented that they made a good team. Yularen was later forced to withdraw due to a renewed Separatist blockade in orbit, but the destruction of the Separatist shield generator and ensuing surrender of General Whorm Loathsom allowed him to return with Master Yoda's reinforcements and secure a Republic victory.

Yularen then assisted General Kenobi in rescuing what was left of Captain Rex's troops holed up at Teth's B'omarr Monastery. He tried to allow Skywalker, his padawan Ahsoka Tano and Jabba the Hutt's son, Rotta to land on his ship but were unable to due to Vulture droids attacking the ship's hangar.

Hunt for Grievous
Yularen played a pivotal role in the search and destruction of General Grievous's secret weapon, the warship Malevolence . After it was revealed Grievous planned to attack the undefended Kaliida Shoals Medical Center, Yularen briefed the pilots of Shadow Squadron, flying BTL-B Y-wings, for their strike on the ship. With the destruction of the Malevolence's massive ion cannons and the disabling of its hyperdrive, Yularen pursued after the ship with three Venator destroyers, including the Resolute, trying to stop it from fleeing to Separatist space, until the ship finally was destroyed on impact with a nearby moon.

Admiral Yularen continued to assist Kenobi and Skywalker in their search for Grievous. Yularen then informed them that the Rishi Station had stopped transmitting and then had the fleet alerted to this problem, which turned out to be an attack orchestrated by Grievous. After discovering that Grievous planned to attack Kamino, the homeworld and production center for the Republic's clone army, Yularen was placed in charge of the planet's blockade fleet. The vigorous orbital defense was successful in damaging much of Grievous' fleet, only to discover the space battle was a Separatist ruse in order to launch a ground attack. Despite this, the planet was successfully defended from the attack.

Later battles
Yularen was involved in multiple other engagements as well throughout the war. He participated in the Battle of Quell, arriving to reinforce the beleaguered fleet of General Aayla Secura, but to no avail. After the Jedi's cruiser inadvertently disappeared into hyperspace, with Secura, Skywalker, Tano, and several clones onboard, Yularen was left to fight on until the battle was lost.

As the Republic moved to liberate Ryloth from the Confederacy, Yularen led the Republic fleet in engaging the blockade, commanded by Neimoidian captain Mar Tuuk onboard a modified Droid Control Ship. The initial engagement saw the loss of the Redeemer while both the Resolute and the Defender were severely damaged, however, he authorized Skywalker's plan to ram the crippled Defender into the Tuuk's flagship, allowing Kenobi's troops to land on the planet. The admiral also coordinated the aerial support for the three-pronged ground assault in the Second Battle of Geonosis, as well as being given command of a task force of Star Destroyers, Republic frigates and Arquitens-class cruisers during the Battle of Saleucami, while the Jedi attempted to rescue the general Eeth Koth, as well as capture Grievous. He commanded the Republic fleet during the Battle of Sullust, where the Resolute was lost to heavy enemy fire. Yularen, however, was able to evacuate before its destruction.

In 19 BBY, Yularen, as one of the higher-ranking Republic naval officers, attended the Republic strategy conference at the starbase Valor over Carida, where he almost perished due to a Separatist plot to ram the station with a captured Star Destroyer. He returned to Coruscant to attend the memorial service for the victims of the Jedi Temple hangar bombing. He was a member of the prosecution, headed by lead prosecutor Admiral Wilhuff Tarkin, in the military trial of Ahsoka Tano, now exempt from prosecutorial immunity after being expelled from the Jedi Order, who was accused of orchestrating the bombing. However, moments before the Supreme Chancellor read the final verdict, the true perpetrator, fallen Jedi Barriss Offee, was brought before the court by Skywalker, and Tano was allowed to go free.

Yularen participated in the Battle of Ringo Vinda, directing Skywalker and his team towards the remains of the destroyed Nu-class transport that had been transporting CT-5385 to Coruscant.

Near the end of the Clone Wars, Yularen would take an interest in Count Dooku and his new right-hand man "Admiral Enigma", who was actually the former Jedi Master Quinlan Vos. After receiving intelligence that Dooku and Admiral Enigma had been sighted on a Providence-class dreadnought that was planning to attack Taris, Yularen informed the Jedi High Council, which had been engrossed in a meeting to discuss rescuing Vos. Using Admiral Yularen's information, the Council decided to rescue Vos and agreed to pardon the former Sith apprentice Asajj Ventress if she agreed to take part in the rescue mission. While the rescue mission was successful, Vos had secretly turned to the Dark Side and become Dooku's newest Sith apprentice.

Imperial Security Bureau
Following the conclusion of the war, Supreme Chancellor Palpatine transitioned the Republic into the Galactic Empire, with himself as Galactic Emperor. With this New Order, Yularen resigned his admiral's commission in favor of pursuing a career with the Commission for the Preservation of the New Order's Imperial Security Bureau (or ISB) with the rank of colonel. His first assignment was heading a division whose purpose was to expose instances of sedition in the Imperial Senate.

By 14 BBY, the fifth year of the Empire's reign, Yularen had been appointed the head liaison between the ISB and its main rival, the Naval Intelligence Agency, and was responsible for ensuring cooperation between the Empire's different intelligence agencies. During this time, he personally reviewed the reports of Naval Intelligence operative Commander Gallius Rax, bypassing NIA Vice Admirals Dodd Rancit and Terrinald Screed. Along with his direct superior, Harus Ison, he represented the ISB on Coruscant when Moff Wilhuff Tarkin arrived to give his report about the attack on Sentinel Base. As the Berch Teller campaign progressed, he continued to play an active role in the Imperial response from Coruscant, conferring with both Tarkin and the Joint Chiefs. After the death of Vice Admiral Rancit at Carida, the Emperor promoted Yularen to replace his rival's former role as head of the NIA when it was folded under Imperial Intelligence, with the position of Deputy Director. In this role, he continued to receive Gallius Rax's top-secret intelligence reports, which were marked "eyes only" for himself.

Visiting the Alisandre Hotel
Following the Dromedar incident, Colonel Yularen accompanied the Lothalian Senator Domus Renking, the Chiss Senior Lieutenant Thrawn and Ensign Eli Vanto during an Ascension Week ball at the Alisandre Hotel on Coruscant. Renking introduced Yularen and his colleagues to one of his aides Arihnda Pryce, who worked at one of Renking's citizen assistance offices. Yularen recounted the story of how Thrawn and Vanto single-handedly captured a pirate ship and most of its crew, and saved a valuable shipment of tibanna gas. While Thrawn was modest about his achievements, Yularen pointed out that Thrawn and his crew were outnumbered by the pirates. When Yularen asked Vanto if he was stating the case, Vanto replied in the affirmative but remained despondent about his lack of promotion.

While making conversation with Renking and Pryce, Yularen announced that he had to leave to attend to business with "friends in high places." Before leaving, Yularen took care to introduce Thrawn to other Imperial officials and senators. Another ulterior motive of Yularen's social call was to help Thrawn build connections with sympathetic civilian officials in order to counterweight the High Command in the event they decided to court martial Thrawn for his ingenious but unorthodox tactics on the Dromedar. Thrawn and Yularen then discussed the matter that twelve of the tibanna cylinders recovered aboard the Dromear had been emptied. Yularen deduced that the insurgent leader Nevil Cygni, who was the insurgent leader Nightswan, had somehow found a way to get the gas out of the cylinders. While Thrawn was upset, Yularen reassured the Chiss that he would be welcome in the Imperial Security Bureau in the event that the Navy did not want him. Fortunately, Thrawn was cleared by the court martial panel, who was subsequently promoted to Captain.

Yinchom Dojo and Higher Skies
Continued their investigation into Nightswan's campaign, Captain Thrawn and Ensign Vanto visited Colonel Yularen's office to seek his help on investigating the wily Nightswan. Yularen shared Thrawn's dismay that Commander Alfren Cheno had taken the fall to protect Thrawn following the Battle over Umbara. Yularen informed Thrawn that he had found multiple references to Nightswan in a range of activities including metal smuggling, antique purchases, and the instigation of protests and unrest. However, he was unable to uncover the insurgent leader's identity. Unable to discern Nightswan's motives, Yularen dismissed him as a troublemaker.

Thrawn speculate that Nightswan was motivated by the usurpation of some personal or mining interests. Following the Circle Bay mayor's office protest, Yularen convinced Thrawn and Vanto to accompany him and the ISB Officers Roenton and Brook on a visit to the dojos that trained bodyguards for Imperial Senators. One of these dojos that Colonel Yularen and his comrades visited was the Yinchom Dojo, which was owned by the Togorian H’sishi. Over the past five years, thirty senators had sent their bodyguards to Yinchom Dojo for training. At the dojo, they met Pryce again, whom they had encountered earlier at the Alisandre Hotel. After losing her job with Senator Renking, Pryce had found work at the Higher Skies Advocacy Group. One of the martial art instructors Juahir Madras at the dojo was a friend of Driller MarDapp, the leader of Higher Skies. Madras was also part of Driller's spy ring, which worked for Nightswan.

When H'sishi arrived, Yularen introduced himself and his companions. He also asked H'sishi whether she had record on government contracts and bodyguard training. Before H'sishi went to fetch the documents, Thrawn convinced H'sishi to engage in a sparring session with sticks. Following the visit, Thrawn related his observations of the dojo to Yularen. He noted that Instructor Madras had ignored them until H'sishi had ordered her to stop. Thrawn also explained that Pryce had alerted him about the advocacy group Higher Skies and that he had sparred with H'sishi to ascertain if she had any hostile intentions. While Thrawn cleared H'sishi of any malevolent intent, he convinced Yularen to investigate Higher Skies.

Following the Yinchom visit, Thrawn secretly met with Pryce, who offered to provide the Imperials with information about Higher Skies' espionage activities in return for immunity. Thrawn agreed to petition Yularen to protect Pryce in return for spying on her colleagues. Acting under Thrawn and Yularen's instructions, Pryce baited Moff Ghadi by offering to provide him with information that Higher Skies had illegally obtained about Grand Moff Wilhuff Tarkin. Pryce then double-crossed Ghadi by exposing Higher Skies' activities and Ghadi's attempted profiteering to Tarkin himself. In addition to granting Pryce immunity, Tarkin agreed to promote her to Governor of Lothal and to promote Thrawn's friend Vanto to Lieutenant Commander.

Following Pryce's deal with Tarkin, Colonel Yularen and several ISB agents arrested members of Higher Skies and Yinchom Dojo including Juahir and the group's leader Driller MarDapp. Yularen personally arrested Juahir after one of the martial arts instructors' students, the bodyguard Kaniki, tried to assassinate Senator Evidorn; after being informed about the "evils" of the Empire by Madras. When Juahir pleaded for Pryce's help, Pryce instructed her former friend to cooperate fully with Yularen in return for being spared the death penalty. However, Pryce convinced Yularen to spare H'sishi since there was no evidence of any wrongdoing on her part.

The Batonn insurgency
Much later, Colonel Yularen along with Admiral Thrawn and Commander Vanto attended a high-level meeting of Imperial admirals and governors chaired by Fleet Admiral Jok Donassius to discuss the Batonn insurgency. Nightswan's insurgents had taken the Imperial garrison on Scrim Island hostage. Thrawn was assigned to deal with the insurgents but insisted on studying the battle longer. Yularen sided with Thrawn and pointed out that the insurgents had disabled the base's cathtron tubes. An impatient Fleet Admiral Donassius then reassigned Scrim Island to Admiral Durril.

Following the failure of Admiral Durril, Thrawn's 96th Task Force successfully defeated the Scrim Island insurgents and forced their surrender. However, several of the insurgents managed to flee to the Creekpath Mining and Refining complex where they holed themselves up. The siege of Creekpath was complicated by the presence of Governor Pryce's parents Talmoor and Elainye Pryce, who worked at the mine. Pryce managed to convince Colonel Yularen to allow her to accompany Agent Gudry on an undercover mission to disable the insurgents' deflector shield generator. Colonel Yularen briefed Thrawn about the plan and the Admiral provided the undercover agents with comms and data collectors.

To ensure coordination between the Navy and the ISB, Yularen agreed to correspond with Commander Vanto on frequencies and passcodes. After briefing Vanto, Yularen asked the Commander about the unusual position of Thrawn's Imperial Star Destroyer Chimaera and the rest of the task force including the disabled light cruisers. Despite the vulnerable position of the ships, Vanto urged Yularen to have faith in Thrawn's tactics. Not fully trusting Thrawn's plan, Yularen asked Vanto to keep an eye on his commanding officer and expressed concern that Thrawn had become obsessed with stopping Nightswan.

Carnage at Creekpath
In secret, Thrawn communicated with Nightswan and the two met at an empty field to discuss a peaceful solution to the siege. Despite their philosophical differences, Thrawn offered to provide Nightswan a means to join the Chiss Ascendancy to safeguard the galaxy against threats from the Unknown Regions. Unwillingly to abandon his men to the tender mercies of Governor Restos, Nightswan declined Thrawn's offer but convinced the Admiral to do his best to minimize civilian casualties at Creekpath. Following the meeting, Yularen picked up Thrawn in his airspeeder and asked Thrawn why he should not shoot him as a traitor.

In private, Thrawn reassured Yularen that he was only trying to seek a peaceful outcome to the Creekpath siege. After being assured of Thrawn's loyalty, Yularen questioned him about the placement of the four light cruisers. Thrawn explained that he had positioned them at a distance so that they would be out of range of any surface attack. When Yularen expressed concern that the light cruisers' positions left them vulnerable to attack, Thrawn responded that this was to prevent theft. Not understanding Thrawn's tactics, Yularen chided Thrawn for his lack of political savvy. Yularen also expressed concern about not receiving any contact from Pryce and Gudry.

Unknown to Yularen, Pryce and Gudry had fallen out. With Gundry reneging on his promise to evacuate Pryce's parents, Pryce had killed him following a struggle. Meanwhile, Colonel Yularen dispatched a special squad to retrieve the two, believing they were in danger. Pryce and her family reached the Imperial lines safely, where they took shelter at Major Talmege's headquarters. Despite the presence of Yularen's special squad and many civilians, Pryce used Gudry's stolen remote to detonate Nightswan's cache of explosives. While this ended the threat of Nightswan's insurgents, many civilians were killed. In space, Thrawn successfully used the four light cruisers as a bait to lure the insurgent fleet into a trap.

Following the breaking of the Creekpath siege, Yularen expressed outrage at the high civilian death toll and likened the incident to the Clone Wars. While official reports theorized that Gudry had detonated the explosives to prevent his capture, Yularen blamed Pryce indirectly for the bombing; unaware that she was directly responsible of the incident. Yularen's forces also found and identified Nightswan's corpse. Yularen and Vanto then departed so that Pryce could talk with Thrawn in private. Pryce convinced Thrawn to take responsibility for the suppression of the Batonn insurgency in return for securing the command of the Seventh Fleet. Thrawn reluctantly obliged and was promoted to the rank of Grand Admiral by the Emperor.

Working with Thrawn
"I would never have suspected one of my best students was capable of this betrayal.''" "''And that is why you and so many others have been deceived."

- Yularen to Thrawn

By 4 BBY, Yularen had returned to the ISB, again with the rank of colonel. ISB Agent Kallus, Yularen's "star pupil" from the Imperial Academy, was after a crew of insurgents known as the Spectres, and answered to Yularen at this time. In 2 BBY, Kallus would secretly join the rebels and provide them Imperial information under the name "Fulcrum." Shortly later, Yularen was invited by Grand Admiral Thrawn to help identify the rebel spy. As part of the screening process, Yularen questioned several Imperial officers on the Sector Command staff in the Lothal sector aboard Thrawn's flagship Chimaera including Captain Brunson, Commander Brom Titus, Lieutenant Yogar Lyste, and his former student Agent Kallus. Lyste and Kallus boarded Thrawn's Imperial Star Destroyer with a captured bounty hunter, who turned out to be the rebel Ezra Bridger.

During a meeting with Kallus and Lyste, Yularen urged his comrades to remain vigilant for any sign of rebel activity. Thrawn also informed the attendees that he was close to locating the Phoenix Squadron's Chopper Base on the planet Atollon. After exiting the meeting, Yularen chatted with Kallus about the identity of Fulcrum. Attempting to deflect attention, Kallus claimed that the rebel spy was an officer and suggested someone in the Communications Division. However, Yularen believed that was too obvious and suspected that Fulcrum had their own communication system. Kallus also promised to help his former mentor. During a private meeting with Thrawn and Governor Arihnda Pryce, Thrawn voiced his suspicion that the spy had attended their interviews. When Colonel Yularen reported that a coded message had been beamed off the Chimaera following the arrival of Lyste and Kallus' prisoner. Yularen then accompanied Thrawn and Pryce to interrogate the prisoner.

Upon arriving in the Chimaera detention block, Yularen and his comrades discovered that the prisoner had been freed. After Yularen found that the records had indicated that someone using Yogar Lyste's code cylinder was the last person to enter the brig, Yularen came to suspect that Lyste was Fulcrum. However, this was a ruse that had been set by Kallus in order to conceal his tracks. After Thrawn narrowly survived an assassination attempt in his office, Yularen was contacted by the Grand Admiral who told him to head towards the hangar with stormtrooper reinforcements. Yularen arrived too late to apprehend the rebels but accepted Kallus' account that Lyste was the rebel spy Fulcrum. Despite Lyste's protests, Yularen ordered his stormtroopers to lead the Lieutenant away.

Due to Kallus' planted evidence implicating Lyste, Yularen initially believed that Lyste was Fulcrum. In public, Yularen regarded Lyste's code cylinder as proof of the officer's guilt. After Kallus and Pryce had exited Thrawn's office, Yularen privately confided his doubts about Lyste's guilt to the Grand Admiral. Thrawn agreed and then presented Yularen with Ezra's helmet, which was inscribed with an image of a loth-cat. When Yularen asked Thrawn why Kallus had withheld Ezra's identity, Thrawn concluded that Kallus was indeed Fulcrum and had framed Lyste to cover his tracks. Yularen expressed shock that one of his former pupils was a traitor, which prompted Thrawn to remark that Yularen had allowed his fondness for his former pupil to deceive him. With Fulcrum "officially" captured, Thrawn decided to allow Kallus to continue operating in order to lure the rebels out of hiding.

Galactic Civil War and death
"Some of the Empire's top people were on that station. Grand Moff Tarkin. Colonel Yularen. So many good men and women."

- Iden Versio, to Gideon Hask following the Battle of Yavin

Yularen was present for a meeting of high ranking Imperial personnel aboard the first Death Star battle station, which concerned the security of the station in view of the recent theft of its technical readout by agents of the Alliance to Restore the Republic in the year 0 BBY. He remained quiet throughout the meeting, even when Grand Moff Tarkin announced that the Emperor had dissolved the Imperial Senate.

Along with another intelligence officer, he later passed by makeshift rebels Han Solo, Luke Skywalker, and Chewbacca, the former two disguised as stormtroopers in an attempt to rescue the imprisoned Princess Leia Organa of Alderaan. Yularen remained onboard the battle station during the Battle of Yavin, where he perished along with thousands of other Imperials when it was destroyed.

Personality and traits
Even by the outbreak of the Clone Wars, Wullf Yularen was regarded by his peers as a crisp, efficient veteran naval officer. Despite his disagreements with the brash and reckless General Skywalker, he held a sacred respect for the chain of command, a trait which made him assist his Jedi General in any way he could.

Colonel Yularen respected the Chiss Imperial Navy officer Thrawn's creativity and ingenious tactics enough to consider him worthy of joining the Imperial Security Bureau. Knowing that Thrawn was an outsider in a xenophobic Imperial Military, Yularen went out of his way to cultivate civilian allies for the alien officer. Still, Yularen was disturbed by Thrawn's unorthodox tactics and willingness to negotiate with the enemy. While Yularen recognized that Thrawn cared about avoiding excessive civilian casualties, he warned Thrawn that his attempt to negotiate with Nightswan could be misconstrued as treason. As a member of the ISB, Yularen actively led Imperial counterinsurgency efforts against undercover insurgents. As a veteran of the Clone Wars, Yularen was horrified by the high civilian death toll during the siege of Creekpath mine, which brought back dark memories of that conflict.

Yularen took pride in the achievements of one of his former pupils Agent Kallus, a promising Imperial Security Bureau Agent. Yularen's investigative skills led Thrawn to enlist his help in exposing the rebel spy Fulcrum. Yularen's trust and respect in Kallus led him to overlook the ISB agent as a suspect. Kallus manipulated Yularen's trust by fabricating evidence which implicated another officer Lieutenant Yogar Lyste. While Yularen privately doubted that Lyste was Fulcrum, he was initially convinced by the presence of Lyste's cylinder code. Yularen was shocked that Kallus could become a traitor to the Empire.

Behind the scenes
Wullf Yularen first appeared as an unnamed background character in Star Wars: Episode IV A New Hope, played by Robert Clarke, and he was given the name Wullf Yularen by the Star Wars Legends card game Star Wars Customizable Card Game. Yularen would later be adopted by the 2008 Star Wars: The Clone Wars film as a recurring character. In that film, the subsequent television series of the same name, and the Star Wars Rebels television series; he was voiced by Tom Kane. Yularen's backstory and subsequent rise to the position of an Imperial Security Bureau Colonel was fleshed out in several Canon novels including James Luceno's 2014 novel Tarkin, Chuck Wendig's 2016 novel Aftermath: Life Debt, and Timothy Zahn's 2017 novel Thrawn. Kane later reprised his role as Colonel Yularen in the Star Wars Rebels episode "Through Imperial Eyes", which premiered on February 25, 2017.

In the StarWars.com Encyclopedia and the Databank, Yularen's first name was spelled "Wulff," rather than Wullf as spelled in the Star Wars Customizable Card Game, thus making the new spelling part of the Star Wars canon. However, Tarkin, a 2014 novel by James Luceno, and Ultimate Star Wars, a 2015 sourcebook published by Dorling Kindersley, use the original Star Wars Legends spelling of his name. This issue was later remedied, with Yularen's Databank page being updated with the "Wullf" spelling.

The character's voice actor Tom Kane compared Yularen in Imperial times to General Erwin Rommel, a German commander in World War II. Rommel's opposite number on the battlefield, Lieutenant-General Bernard Montgomery, respected the German commander and said that even though Rommel wore the Nazi uniform, he wasn't a Nazi. Kane believed that Yularen, a strict military officer, was simply following orders when the Republic transitioned into the Empire.