Sometime after the Harmonic Convergence of 171 AG, Yung began manifesting newly acquired airbending abilities. However, he was subsequently captured by the Dai Li, who imprisoned him in a secret facility under the Earth Kingdom Royal Palace, intending to train him to become a part of the Earth Queen's army.
During his training, as his partner, Kai, prepared to attack him, Yung pleaded with him to go easy on him, confessing that he was not very good. Kai in turn fired a light blast of air at Yung which the young boy easily managed to dodge. However, the Dai Li sergeant that was overseeing their training forced Kai to attack Yung harder, causing the him to fall to the ground in pain. Later that day, the Dai Li sergeant continued Yung and the other airbenders' training by firing earth discs at them. As the agent fired a disc at a fearful Yung, Kai intervened and airbent the projectile away from his compatriot. Yung thanked Kai for his help, but was subsequently forced to watched on as Kai faced an onslaught of discs before being sent to solitary confinement.
Later that evening, Korra, Tenzin, and Bumi broke into the facility the airbenders were being imprisoned in order to save them. Yung informed them that Kai had been taken to a separate location. He was consoled by Tenzin, who assured him that they were already taking care of finding Kai, and Yung promptly followed his rescuers out of the prison. However, as they exited, they were confronted by a number of Dai Li agents and the Earth Queen herself. The queen ordered the group be restrained, but Yung and the other airbenders used their new abilities to push the agents back, and were saved when Lin arrived in a police airship. Upon escaping Ba Sing Se, Tenzin offered the new airbenders a chance to train at the Northern Air Temple; after a few seconds of hesitation, Yung was the first to accept the airbending master's offer, quickly followed by the others.
At the Northern Air Temple, Yung was alongside the other airbenders during training. He was particularly impressed by the demonstrations of bison flight provided by Tenzin on Oogi, but was disappointed to learn that mastering control over one required years of training. Later, he and other airbenders were listening to Bumi share one of his military stories. Yung asked Bumi why he was so cool unlike Tenzin, before walking away when Tenzin came to ask Bumi for advice. The next morning, he and his fellow airbenders were forced into more rigorous training, such as a ten-mile walk which left him exhausted and cold, wishing the robes came in a warmer, bison fur pelt.
After Tenzin told the group about shaving their heads, Yung was not sure about getting it done, to which Tenzin said it was optional, prompting him to decline. He soon tried the obstacle course, making his way up to the rash cacti section, but fell of a post when Kai collided with him. Covered in mud, he expressed a desire to change his robes. He and the airbenders were eventually left under the direction of Meelo as a frustrated Tenzin walked away.
Later, Tenzin asked Yung and the other airbenders if they had seen Jinora. Yung said he saw Jinora ran off with her boyfriend, which caused Tenzin to be slightly agitated. After Bumi found out Jinora and Kai were in trouble, Yung joined him and the other airbenders in an attack on a bison rustlers camp in order to free the kids and some bison calves. After they completed the mission, Yung regathered with all the benders to relax and listened to Daw trying to persuade him and the others to shave their head as well.
When the Red Lotus attacked the Northern Air Temple, Yung was imprisoned with all the temple's inhabitants in a cave-complex a few miles away from the building. He was released from his shackles by Team Avatar when they burst through the cave wall and took down the Red Lotus sentries sanding guard. Yung exited the caves and, upon Jinora's command, he formed a circle with the other airbenders and helped to create and maintain a powerful tornado that enabled AvatarKorra to slam Zaheer down on the ground, ending the fight. He subsequently watched as Suyin bent most of the mercury out of Korra, saving her life.
Two weeks later, Yung took part in Jinora's anointment ceremony as an airbending master on Air Temple Island. He listened with pride to Tenzin's speech of how the Air Nation would reclaim its nomadic roots and roam the earth, promoting peace, balance, and harmony while Korra recuperated from her fight with the Red Lotus. When Tenzin revealed Jinora's mastery tattoos, Yung bent the smoke from the incense sticks behind him and guided them through the temple hall, tingling several wind chimes in recognition of the new master.