|"Justice, Kyoshi, [...] I want justice. Everyone who lied to me is going to suffer the consequences."|
|— Yun telling Kyoshi about his ongoing quest for vengeance.|
Yun was the friend of Kyoshi and Rangi and the earthbending pupil of Jianzhu. Talented, charismatic, and handsome, he was misidentified as the new Earth Avatar after a long and difficult search. Following the revelation of Kyoshi's identity as the true Avatar, Yun was betrayed by Jianzhu, who felt the boy's usefulness had been exhausted and allowed Father Glowworm to carry him off in the mountains.
Broken and enraged by the fact that he was not the true Avatar, Yun started a vengeful quest to kill all the bending masters and politicians who had lied to him about his Avatarhood. Determined to put an end to Yun's destruction, Kyoshi confronted him with her companions in a great battle that destroyed the Avatar mansion and injured many of Kyoshi's friends. Although Kyoshi managed to kill Yun, she was heartbroken that Yun had been corrupted by vengeance.
Identification as the Avatar
When Yun was around fourteen years old, he was discovered in Makapu Village by Jianzhu and Kelsang while playing Pai Sho. He repeatedly bested tourists in the game by utilizing the late Avatar Kuruk's favorite strategies down to exact tile placement, which led Jianzhu to presume that Yun was Kuruk's reincarnation. He was subsequently taken under the protection of the two men.
At sixteen years old, Yun was prodigious at earthbending but had yet to show any signs of bending the other elements. Despite this, Jianzhu was confident in his identification as the new Avatar, claiming Yun to be everything Kuruk was not and committed himself to teaching him all he found imperative for the Avatar to know. For this purpose, Jianzhu erected a mansion near Yokoya Port to house Yun and his entourage. During this time, Rangi, the daughter of Yun's firebending teacher, Hei-Ran, and Kelsang's adoptive daughter, Kyoshi, were assigned as his bodyguard and maid, respectively.
Under the tutelage of Jianzhu, Yun underwent many rigorous and painful tests: bending exercises, physical trials, meditation, as well as poison training. He was even trained by his waterbending teacher, Amak, to be a killer in order to protect himself from daofei, spies, and assassins. These lessons did not just include combat training, but also the intake of small amounts of poison so that Yun could build up an immunity. Yun actually liked training with Amak, considering him a blunt yet effective and direct teacher. In between lessons, Yun regularly journeyed around the world with Jianzhu and Kelsang on the latter's flying bison, Pengpeng, in order to meet important people from the four nations. His two male mentors wanted to ensure Yun had a cosmopolitan upbringing, as the ideal Avatar was also a diplomat without bias.
Dedicating his whole being to his Avatarhood, Yun spent sleepless nights poring over scholarly analyses of Yangchen's political decisions. He exhaustively memorized the names of every Earth Kingdom noble, Fire Nation commander, and Water Tribe chieftain among the living and three generations of the dead. Yun used forgotten texts to map the ancient sacred sites of the Air Nomads to such a degree that it even surprised his airbending mentor, Kelsang.
In 296 BG, Yun's earthbending had improved to the point where he managed to catch a jar of kelp that Kyoshi's bully, Aoma, threw into the air from afar. Immediately afterward, he used his bending to communicate with Kyoshi and Rangi, even though they could not respond. After observing Rangi being annoyed with Kyoshi, Yun acrobatically returned to the training grounds, where an unimpressed Hei-Ran criticized him for letting his mind wander. He then attempted to achieve firebending only to end up using earthbending to mimic it. As Hei-Ran remarked that masters used to maim their students for insubordination in the old days, Jianzhu intervened and insisted they take a break.
Retreating to the largest storage area, Yun was then informed that Tagaka of the Fifth Nation had agreed to sign a new version of her great-grandfather's treaty, agreeing to the cessation of raiding along with the Xishaan Mountains in exchange for access to timber on Yesso Island, all based on his Avatarhood. Yun noted that the Fifth Nation would still be able to assault Chameleon Bay or the Fire Nation. When asked if he intended to reject Tagaka's offer, he concluded that they had to accept for the Fire Navy to deal with the Fifth Nation, though he was uncomfortable with manipulating the very nations he was supposed to protect, despite Jianzhu's endorsement of his strategic thinking.
Returning to his firebending training, Jianzhu forced Yun to walk across a spike floor barefooted to disconnect him from his native element. Afterward, he proceeded to find Kyoshi for aid in sorting out the various gifts in his quarters. When they started arguing over a pair of oversized boots, Yun pleaded with Kyoshi to join him on the upcoming treaty signing, as he needed a regular person to observe him as a friend, not the Avatar.
As Kyoshi consented to join him, Yun briefly took her fingers to his cheek, causing her to flush, before anticipating Rangi's entrance. As the firebender bowed before Yun and criticized Kyoshi for failing to make any progress cleaning up, she and Yun started to joke about burning down the mansion before Rangi threw a decorative pillow in his face, causing the trio to burst out in hysterical laughter.
Fall of the Fifth Nation
While flying to the meeting point via Pengpeng, Yun narrowly caught Kyoshi from falling off after she woke up from a nightmare. Eventually, they arrived at the iceberg Tagaka had chosen for the negotiations, where Yun ran into Amak who had disguised himself as one of his guards. Upon meeting the Fifth Nation leader, Yun's party was invited back to Tagaka's camp for a feast in his honor. Midway through the banquet, Tagaka remarked that she assumed she was going to be killed before the treaty. Yun assumed she was referring to his contingent of bodyguards, only to be caught off guard as Tagaka openly accused his bending masters of mass murder. First, she revealed that Jianzhu was called the Gravedigger of Zhulu Pass, not for respectfully interring the Yellow Necks' victims, but for burying 5 thousand daofei alive. She then revealed that Hei-Ran had a high record of "accidental kills" during Agni Kais and that Kelsang violated his pacifist beliefs by devastating a Fifth Nation fleet. Managing to regain his composure, Yun diplomatically responded that she had nothing to fear from his masters.
Once Tagaka and her bodyguards had departed for the night, Yun immediately confronted Jianzhu as to the veracity of her claims. His earthbending master shamelessly defended his actions, declaring his actions against the daofei who believed themselves beyond justice had served to drive the remnant of the Yellow Necks into hiding, and argued any decent Earth Kingdom citizen would agree with him. But as Kelsang supported Jianzhu's argument, reasoning his teachers had to act without an Avatar years after Kuruk's death, Yun flippantly retorted that the burden of killing without mercy had been shuffled onto him, which only earned him a reprimand from Jianzhu for letting Tagaka rattle him. The rest of their party were dismissed save for Yun and Jianzhu as they furiously began to argue.
The next morning, Yun attended the treaty signing and began proofreading Tagaka's document. However, he spontaneously demanded Tagaka release all her Earth Kingdom captives, in direct defiance of his prearranged discussion with Jianzhu. Surprisingly, the Fifth Nation leader readily agreed, revealing that the whole treaty signing was a ruse to lure Yun away from Yokoya so the Fifth Nation can invade and take the carpenters and timber needed to expand their fleet. Suddenly, Tagaka killed Amak, having seen through his disguise, before her waterbenders pulled Rangi, Hei-Ran, and Jianzhu under the ice. Yun managed to create an earth glove out of the stone ink slab on the negotiating table and began to duel Tagaka, who then unveiled her hidden fleet within the iceberg about to set sail for Yokoya. In desperation, Yun urged Kelsang to stop the ships instead of aiding him, but Tagaka managed to damage his glider, causing him to fall in the sea before the waterbender encased Yun in a block of ice.
A captive Yun was soon brought back to Tagaka's camp, where Kyoshi confronted her and demanded Yun's freedom. The Fifth Nation leader remarked that Yun was worth more as a hostage than an Avatar, disrespectfully shoved him off to the side. Suddenly, Kyoshi managed to earthbend the very seafloor, devastating the Fifth Nation fleet. Rangi and Hei-Ran then showed up and free Yun and together managed to defeat Tagaka.
Afterward, Yun and his allies returned to Yokoya, where Kelsang confessed his suspicions of Kyoshi being the true Avatar. While awaiting Kyoshi to regain consciousness after passing out on the iceberg, Yun was attended to by healers, who mistook the ink stain on his hand for frostbite. Days later, he was visited by Kyoshi and proceeded to update her on the events that had passed in her absence. Just as his maid started praising him for defeating the Fifth Nation, she was interrupted by Rangi, who revealed what Kelsang told them. As she started accusing Kyoshi of potentially discrediting Yun and Jianzhu, she unintentionally began burning through her chest with her finger before recoiling in horror at what she had done and leaving in shame. Yun then attempted to speak to Kyoshi only to hesitate and leave her side as well.
Sometime later, Jianzhu suspended Kyoshi's duties until he could figure out which teenager under his roof was the Avatar. Following her first failed attempt at firebending, Yun learned that she was spending her free time hiding in the mansion's library. Recognizing his friend's guilt at potentially stealing his Avatarhood, he tried to reassure her that she was not at fault. Though Kyoshi rebuffed that Rangi had yet to forgive her, Yun maintained confidence that the firebender would come around, given that she was "a person of faith".
Yun then started talking about the political infighting among the Earth Sages, some of whom only want to influence the Avatar to increase their own political power. It was only his hard work with Jianzhu that acted as insurance against any sage trying to see them separated, but if his Avatarhood was proven false, then essentially every treaty and peace agreement the two of them had crafted would be rendered null and void.
His words caused uncertain silence between the two of them before Yun noticed a porcelain bowl filled with fire lilies, reminding them both of the time eight months prior when they almost kissed each other. Seeing this put a smile on Kyoshi's face, and he assured her that he would be happy for her if she was proven to be the Avatar.
Later that afternoon, Jianzhu took Yun and Kyoshi on a clandestine trip to an abandoned mining town in the Xishaan Mountains without informing anyone in the mansion. Yun assumed they were going to attempt to trigger the Avatar State, only to be told they were going to commune with a suffering spirit. Upon reaching the terrace atop the nearby mountain, the two teenagers were ordered into a meditative stance; Jianzhu requested they light his incense stick with firebending, causing awkward silence that forced him to light it himself. As they closed their eyes and inhaled the incense, Yun tried telling Kyoshi something important, only for both of them to be drugged by the incense.
Jianzhu soon summoned the spirit he called Father Glowworm, requesting it identify which teenager was the true Avatar. Managing to regain mobility thanks to his poison training, Yun threw himself between Kyoshi and the spirit, but Father Glowworm took both their blood regardless and confirmed Kyoshi as the true Avatar. Those words devastated Yun, having never considered his Avatarhood was false. Suddenly, Jianzhu assaulted Father Glowworm and dragged Kyoshi away, enraging the spirit, who declared that it was raising its blood price as one of its tendrils coiled around Yun and dragged him into the cave, leaving his companions to assume him dead.
Duel in the Spirit World
When Yun came to his senses, he realized that he was in the Spirit World. Yun attempted to appease the spirit and convince it to become its teacher in hopes of finding a way back to the mortal world. Despite seeing through Yun's ruse, Father Glowworm initially humored him by accepting the human's compliments, but then cruelly told him that he was nothing. Father Glowworm promised that part of him would achieve immortality by being subsumed into the spirit.
Father Glowworm subsequently attacked Yun, who managed to resist for a considerable amount of time, managing to deflect the spirit's attacks with torrents of skillful earthbending. Eventually, the spirit proposed a truce, which Yun accepted, confident in his ability to make deals with others. The spirit promised to grant Yun a portion of its power to create passages between the realms, in return for bringing it innocents to feed on. Yun accepted the deal, but at the last moment, raised the floor of the spirit grove with his raw strength and crushed the spirit. As Yun ate Father Glowworm's eyeball, he absorbed the spirit's essence and gained its powers.
Desperate to escape the Spirit World, Yun relentlessly dug down until he awoke in the physical world in a hillside near a mining village in the Xishaan Mountains. A ragged Yun made his way to the well in the center of a village, where a guardsman informed him that he could only drink from the governor's well if he had appropriate tags. He attempted to make a bargain with the man, but at that moment realized that he had nothing to offer, as none of the Avatar's wealth was his.
On his way to the teahouse, he realized that he could sense that Kyoshi was in the Taihua Mountains thanks to an innate connection between Father Glowworm's essence and Kuruk's reincarnation. He also determined from a worker's conversation that he had seemingly spent only a week in the Spirit World, despite having perceived his duel and subsequent escape as having lasted much longer. Entering the establishment, he was told to leave as soon as he revealed he had no money to pay for water. He told the owner that he was in fact Yun, and the man responded by cruelly asking him to waterbend if he wished for a drink of water. Yun snapped, declaring that he dedicated his life to everyone in the teahouse, such as a patron who had been kidnapped by Tagaka. An increasingly scared mine shift leader offered him her water to diffuse the situation, but Yun declared it was too late to make amends. He formed a blade out of the ceramic pots around the teahouse, killing the owner and other patrons before doing the same to the guard by the well, determined to start a vengeful crusade against anyone who had lied to him about his Avatarhood.
Quest for vengeance
Sometime later, Yun appeared at the famous stone teahouse in Qinchao Village, much to the shock of Kyoshi and Jianzhu, who had been battling each other. Although he looked unscathed, faintly smiling even, Kyoshi felt something essential and human was missing from him. Without a word, Yun calmly picked up a small earth bullet, pressed it against Jianzhu's chest, and forced it through his former mentor's body, killing him. He subsequently walked away with a smile on his face and, before vanishing, hit the wall to alert the patrons of the events that transpired.
Over a year later, Yun appeared again at the Fire Nation Royal Palace, while Fire Lord Zoryu was receiving Kyoshi for the Festival of Szeto. He cheerfully claimed to have an invitation to all Festivals of Szeto, asking Zoryu if the offer had been retracted because of his supposed death. Rangi ordered him to come down, and Kyoshi tried to bring him aside to talk, but Yun had the Fire Nation nobility held hostage, having sunk them all into the floor with his bending.
Kyoshi and Rangi began to fight Yun, running after him after he leaped into the crowd. As the Avatar approached him with her war fans, he used a Fire Nation minister as cover, surprised that Kyoshi tried to hurt him. As she alternated stabs at his head and body, he sarcastically asked for thanks in defeating Jianzhu, reminiscing about his death. Kyoshi asked what he wanted from her, and he responded that he wanted justice from everyone who lied to him about being the Avatar. At that moment, he tunneled beneath the floor, determined to find the masters that had deceived him.
Although Kyoshi and Rangi rushed to Hei-Ran's chamber before Yun, he had managed to kill Lu Beifong in the interim, dropping his body to the floor of the portrait gallery. Dairin's men surrounded Yun, believing he was without material to earthbend, but he made use of the earth-based pigment in the portraits of the Fire Avatars, holding the blob of paint above his head before he shattered it into sharp pellets that knocked back both Kyoshi and the guards, injuring and killing many of them, including Dairin, and using the opportunity to disappear.
In the next few days, Yun made his way to North Chung-Ling, where Hei-Ran had retreated to after the attack on the palace. He crafted a diversion by creating a message championing Chaejin's claim in the melonyam fields to provoke the Keohso and Saowon clans into fighting, while he met with Hei-Ran alone in her inn. Kyoshi caught Yun and Hei-Ran amid a Pai Sho game, the former declaring he would win in eighteen moves. He reformed the Pai Sho tiles into a single spike, pointing it at the base of Hei-Ran's neck. Kyoshi pushed against the blade with her own earthbending, but despite her resistance, he managed to sink the dagger into Hei-Ran's throat. Despite her wound, she grabbed Yun by the wrist, summoning a ball of flame and thrusting it at Yun's torso. He hissed in pain, shoving Hei-Ran to the floor and withdrawing the dagger. He escaped from the second story, Kyoshi choosing to help Hei-Ran rather than go after Yun.
Final battle and death
One month later, Yun returned to Yokoya at the semi-abandoned Avatar mansion. Kyoshi managed to sense Yun's location after she connected with Kuruk's memories of Father Glowworm, and he left a message so that she could find him inside the estate. Kyoshi approached him as he was being served a plate of dumplings by Mui, who was ecstatic to see both Yun and Kyoshi after so long. The pair found an excuse to dismiss Mui and began to confront one another. Kyoshi resolved to put Yun away, stating that if he resurfaced, the Fire Nation would fall into chaos again. Yun responded that he did not care about the state of the world, and was determined to kill all the liars who had sought his favor while he was believed to be the Avatar. Not wishing to be locked up by Kyoshi, he told her he was not being given much of a choice to fight her or not; Kyoshi responded that she was not giving him a choice.
Yun bent up a stone pillar between him and Kyoshi, providing ample bendable earth for the two of them. Both started punching bullets and fist-sized rocks at each other from the monolith, both sides managing to avoid attack until Kyoshi shoved the entire pillar at Yun, ripping up the dining room. Yun escaped from the area, earthbending spikes at Kyoshi from the central part of the estate while not letting himself be seen. As Yun emerged from an alcove, Kyoshi asked him to let go of his pain, which he refused.
He liquefied the stone floor of the main hall without heat, bringing it up to trap and encase Kyoshi. He explained that he never intended to hurt her, as she was the only one innocent in the entire affair. Pointing out her heavy armor, he believed that she had been cursed by her newfound Avatar duties. Kyoshi proudly responded that she wore her makeup and armor because she chose to, and she had much truer friends than Yun.
At that moment, Kirima's water whiplashed down, allowing enough time for Wong to successfully earthbend Kyoshi out of Yun's trap. As Kirima rained water down, he protected himself with a slab and sent it flying at her, while moving away by bending the ground beneath him. Caught off-guard by Kyoshi's friends, he asked if Rangi was here, to which the firebender confirmed, as Jinpa circled above the mansion on Yingyong.
Kirima sent a fresh torrent at Yun, who bent a new shield, which was deflected by Wong. Kyoshi tried to drag him down with earthbending, but he easily escaped from the ground and managed to shatter a great mass of stone tiles with a flick of his shoulders when Wong brought the flooring down upon him. Rangi stepped forward, breathing forth a great blast of fire, Yun sliding off to the side riding a swell of earth. Rangi ran the fire after Yun as he escaped, the earthbender caught off guard by the ferocity of her attack.
In response, Yun violently shook the earth, sending Kyoshi and Rangi flying. As he liquefied the very foundations of the mansion, Wong and Kirima were forced from the roof, while Jinpa finally came in from above to rescue the combatants. Yun launched a hedge of stone spears, launching them at the airbender and managing to run him through the shoulder, pinning him to his bison's saddle horn. Kirima and Wong rushed to Yun, trying to attack him from a blind spot, but he created large pitfalls that broke their legs.
Yun hurled broken earth discs at Kyoshi and Rangi, now attempting to chastise them instead of truly wound them. The pair then crudely put on a substitution of their signature makeup with blood, and began to jet-step with firebending, propelling themselves forward to Yun without touching the earth. Kyoshi shot a huge fireball in Yun's direction but managed to miss, yet Rangi managed to redirect the flame's course and hurled it back around, causing Yun's earthen barrier to explode. Yun tunneled down and made his way up to Rangi, stabbing her through the back with an earthen spike.
As Kyoshi cradled her girlfriend in her arms, Yun warned Kyoshi that situations would keep occurring if she tried to stop him. Kyoshi began to apologize for stealing Yun's Avatarhood, bringing a hand to his chest to comfort him. Finally, she used an advanced healing technique to drastically lower his body temperature, freezing his heart and lungs solid and killing Yun, putting an end to his crusade once and for all.
Kyoshi buried Yun on a hill above Yokoya, personally engraving his name and place of birth on the stone marker. Kyoshi and Rangi were the last to linger by Yun's grave after a small funeral.
Yun's role in escalating the Camellia-Peony War was used by Fire Lord Zoryu as a pretense to denounce the Saowon clan as traitors, and motivated him into starting a generational effort to undermine the power of the noble clans and concentrate all authority in the Fire Nation under the Fire Lord.
Yun was described as a young man with jade-green eyes, brown hair, and a handsome face with sharp edges. He had an easy smile and warm eyes that twinkled with mischief. Kyoshi described him to have had a solid physique. During his fight with Tagaka, he accidentally tattooed one of his hands gray after using an inkstone as glove. Later, having returned from the Spirit World, his skin had a healthy glow, and he had neat stubble lining his jaw, though he was surrounded by an aura of inhumanity.
Yun was generally a fun-loving playful boy who liked to tease his friends Kyoshi and Rangi. He was also quite wise and took his Avatar duties seriously, even though he grew increasingly frustrated over his inability to bend anything other than earth. Jianzhu described him to be a great strategist, having the insight to think ahead and identify people's weaknesses and strengths.
While charming and cheerful on the outside, Yun was insecure about his position as the Avatar and became stressed when Kyoshi was revealed as the true Avatar. He tended to hide his true feelings from others, as evidenced by his lie to Jianzhu about being happy for Kyoshi if she were to be the true Avatar even though it crushed his spirit. Kyoshi considered him to have an easygoing nature and an inability to hold a grudge.
After his duel with Father Glowworm, Yun was corrupted by a passion for vengeance. He considered himself free of the burden of having to care about the state of the four nations. Yun's once playful nature turned to biting sarcasm, and he was willing to kill others simply to warn people about not interrupting his vengeful crusade. He was deeply plagued by his insecurities until the end, and Kyoshi took advantage of this when she apologized for "stealing" his Avatarhood before she killed him.
Yun was an extremely skilled earthbender, possessing a great amount of raw strength as well as a proficiency for finesse. He developed a new technique of writing with earth to communicate from long distances. Yun was also capable of other extremely rare earthbending abilities, such as using seismic sense, bending mineral-based pigments, and liquifying stone without using heat.
Yun was also an expert Pai Sho player, as well as a skilled diplomat, known for being able to make deals that left both parties satisfied.
- Yun always refused to talk about his blood relations, making Kyoshi believe that Jianzhu was both his mentor and his family.
- Yun owned forty-four Pai Sho boards.
- Yun's appearance was heavily inspired by the Chinese fiction wuxia heroes.
- According to Michael Dante DiMartino, the idea of a false Avatar was repeatedly pitched since the start of Avatar: The Last Airbender, but "there was never an angle we could figure out that made sense." As a result, when F. C. Yee managed to work it into the story about Kyoshi's early life, the false Avatar found DiMartino's full support.
- Yun was a dedicated Avatar scholar who knew about many past Avatars.
- Yun's merger with Father Glowworm is one of the only known instances of a human absorbing a spirit besides the Avatar. As spirits cannot truly die, it is unclear what happened to the merged spirit of the two after the death of Yun's body. In the case of the Avatar, the connection between the mortal and spirit endured beyond death and led to a reincarnation cycle.