Avatar: The Last Airbender is a show centering around a war that has lasted for a hundred years, so it should come as no surprise that there are many characters with tragic backstories. The stories of orphans, refugees and prisoners of war are told throughout the series. However, Avatar: The Last Airbender was an animated show primarily directed at children, so the true gruesomeness of war was often glossed over.
The novels focusing on Avatar Kyoshi are not restrained by network censors like the animated series, allowing the novels to be far more violent and graphic than the animated show. This new level of maturity allowed the writers to create characters that truly feel like they live in a world filled with strife and conflict. One of these characters is Yun, whose story is truly heartbreaking.
Yun's story did not begin with tragedy but started with hope. After replicating Avatar Kuruk's Pai Sho strategies, Yun was assumed to be the next Avatar. Kyoshi actually served as Yun's maid, and the two of them became close friends. Yun was taken in and raised by his bending masters, who were dedicated to turning him into the greatest Avatar. Besides bending, Yun eagerly learned about the histories of the Avatars, world politics and the personal histories of each nation's leaders.
Yun's Avatar training was often extremely difficult and even abusive at times. He was made to ingest small amounts of poison so that he could build up immunity. One of his teachers even forced him to walk across a spiked floor in the hopes it would help him activate his firebending. Because Yun was not truly the Avatar, none of his training allowed him to use any of the other elements besides earth. However, the training was not completely useless, as Yun became a true earthbending master.
In fact, Yun's earthbending skills were so impressive that if he and Toph lived during the same era, he could have possibly usurped the blind bandit for the title of "World's Greatest Earthbender." Yun could use seismic sense, bend the earth-based pigments from a painting, and even liquefy stone with no heat. His style of fighting was even taught to the Dai Li by Kyoshi. When tragedy finally struck Yun, these skills would be used against the world instead of to protect it.
During a confrontation, Kyoshi demonstrated earthbending abilities that made Yun's masters suspect she might be the true Avatar. One of Yun's masters, Jianzhu, brought Yun and Kyoshi to meet with a spirit to figure out which of the two was the real Avatar. When the spirit determined that Kyoshi was the Avatar, Jianzhu allowed the spirit to take Yun into the Spirit World.
In the Spirit World, Yun was almost consumed but managed to defeat a spirit and eat part of its body. This allowed Yun to escape the Spirit world but also caused him to lose his humanity. Once back in the real world, Yun saw how poorly others treated him when they realized he wasn't the Avatar. This, along with Jianzhu's betrayal, motivated Yun to go on a bloody quest of vengeance against his masters.
In a similar manner to Zuko, Yun was a kind and honorable young man who was corrupted by the abuse and manipulation of those he trusted. Yun possessed a great deal of potential that could have been used to make the world a better place. This only makes his fall from grace all the more tragic. Yun was groomed to be the best Avatar there ever was, and he worked hard to make that goal come true. If Yun had actually been the Avatar, he probably would have done a fantastic job. However, through a series of misfortune and betrayals, Yun was transformed from hero to villain.
