Following Chit Sang's detainment in the cooler for firebending, the Warden came to him and warned him not to try to escape, stating that he would "sooner jump in the boiling lake himself than let that record fall".
Later, when it was discovered that Zuko had disguised himself as a guard, the Warden came to visit him, instantly recognizing him. When Zuko asked him how he knew his identity, the Warden revealed that he was Mai's uncle. He then told Zuko to behave, cautioning that if "the other prisoners found out who [he was], the traitor prince who let his nation down, they'd tear [him] to shreds". Zuko asked why he did not just tell Fire LordOzai and collect a reward, to which the Warden stated that he intended to eventually turn Zuko in.
He later discovered Chit Sang's escape attempt when the latter screamed after being burned by the lake's scalding water. He ordered the escapees be recaptured and placed in coolers, and that the entire prison be placed on lock-down, due to the fact that there were new prisoners arriving.
The Warden greeted the new prisoners upon their arrival. In his usual arrogant fashion, he told them that their time in the Boiling Rock would be pleasant, so long as they behaved. He stopped at Hakoda, who refused to look him in the eyes, and ordered him to do so. After being tripped by the Southern Water Tribechief, he angrily ordered the prisoners into their cells.
Afterward, he went to interrogate Chit Sang about the escape attempt. Chit Sang angrily declared that he would not talk, unwittingly revealing that there was another conspirator. The Warden proceeded to have Chit Sang tortured, by being held upside down until the blood rushed to his head, until he confessed. Eventually, the prisoner succumbed to the torture and revealed that it was a man disguised as a guard who came up with the plan.
The Warden forced Chit Sang pick the impostor out of a line up, unaware that guard Chit Sang accused was, in reality, not responsible. He proceeded to interrogate that guard until he was interrupted by PrincessAzula, who told him that the guard he was interrogating was not the mastermind behind the escape plan. When asked how she knew, she simply replied that she was a "people-person".
Much to his dismay, the Warden arrived at the prison yard to discover that all prisoners had been released from their cells, despite his earlier lock-down order, and that a riot was ongoing. Unaware that the chaos was the foundation for an escape attempt, he left to take control of the situation, but was captured by Suki who, alongside Sokka, Hakoda, Chit Sang, and Zuko, was absconding from the prison. The five of them used the Warden as a hostage to safely board the gondola.
While riding the gondola, the escapees were confronted by and forced to contend with Azula and Ty Lee, who had arrived on scene. During the scuffle, the Warden managed to break free from his restraints and yelled for the other guards to cut the line, preferring to die than have his record broken. Chit Sang and Hakoda managed to restrain him, but not before the order was given and the guards began cutting the line. However, Mai intervened, saving Zuko and the others from certain death. The gondola managed to cross the lake where the escapees fled with Hakoda telling the Warden that his record was officially broken.
After Ozai was overthrown and the Hundred Year War ended, the Warden somehow managed to earn his niece and Ty Lee their freedom, which showed that even after Mai had assisted in the escape that ruined his record at the prison, he still cared for his niece.
The Warden, who was the highest official of the Boiling Rock prison, was very demanding and impatient, yet skilled at what he did. He was particularly proud of the no-escape record of the Boiling Rock, a record he would die to keep. He was very bossy and demeaning when he talked to prisoners and guards, only treating prisoners well on a few occasions, but mostly in condescending ways. Despite his obvious lack of kindness, he may have had a softer side as Mai said that he managed to pull some strings to free her from prison, despite the fact she helped Zuko, Sokka, and the others escape the Boiling Rock, thereby shattering the Warden's otherwise perfect record of inescapability. He also seemed to have cared for his family, as he was angry that Zuko broke up with Mai.
The Warden was voiced by American actor Wade Williams, who has a starring role as Captain Brad Bellick on Fox's television series Prison Break, about a man jailed for a crime he did not commit, who then tries to escape from prison.
During the previews at the New York Comic-Con in 2008, it was revealed that his design is based on one of the show's staff members, Oh Seung-hyun.