Zuko is a skilled Firebender and the son of Fire Lord Ozai, ruler of the Fire Nation. Before the events of the series, he is exiled from the Fire Nation and sent to capture the Avatar; he is initially bent on capturing Aang in order to restore his honor and right to the throne in the eyes of his father. Zuko was accompanied and advised in his search by his uncle Iroh.
Although initially portrayed as an antagonist of the series, Zuko's sense of honor has caused him to go against his own nation and family. Zuko is also revealed to have an important connection to the Avatar. To that, he has realized that his real destiny is to join the Avatar to end the war and to teach Aang firebending.
Zuko was born to Princess Ursa and Prince Ozai. Always favored by his mother and neglected by his father, Zuko developed a close bond with his mother. Around six years before the series takes place, Zuko learns of the death of his cousin, Lu Ten, in battle during the siege of Ba Sing Se. This results in his uncle giving up the siege in grief and Zuko's father Ozai sees this as a chance to convince Fire Lord Azulon that he should inherit the throne. Ozai's request is denied and as punishment for attempting to exploit Iroh's loss, he is ordered to kill Zuko. However, Azulon dies and Ursa disappears before anything happens. It is later learned that Ursa came up with a plan in which Ozai became Fire Lord and Zuko's life would be spared. This apparently led to Azulon's death and Ursa was banished as a result of it. The next day, Zuko demands to know where Ursa is but receives no answer. He is later present at Azulon's funeral and Ozai's crowning as Fire Lord.
Three years later, Zuko's uncle allows a thirteen year old Zuko to enter a war meeting. Zuko, upon hearing of a plan to sacrifice novice troops in battle, speaks out against the plan. Ozai demands Zuko duel in an Agni Kai, but when the duel begins, he finds himself unable to duel his own father. His father, seeing this as weakness and disrespect, scars Zuko, strips him of his birthright, and exiles him, under orders not to return unless he captured the Avatar.
Book 1: Water
Zuko first appears searching for the long lost Avatar with his Uncle Iroh and some crew members. After seeing a glow at the South Pole, he heads there, where he captures the Avatar but then loses custody of him. Throughout most of Book 1, Zuko pursues Aang but the Avatar evades him every time. Zuko also has to deal with his rival, Admiral Zhao, who does whatever he can to hinder the prince's progress. Zhao at one point successfully captures Aang, but Zuko frees the Avatar under the disguise of the Blue Spirit. Once Zhao discovers that Zuko and the Blue Spirit are the same person, he attempts to assassinate Zuko but fails. Zuko covertly stows aboard Zhao's ship with help from Iroh and infiltrates the North Pole. He captures the Avatar but his friends rescued him and captured Zuko. After escaping, he duels with Zhao for trying to kill him and is soon ended when the vengeful Ocean Spirit pulls Zhao under the surface as revenge for killing Tui, the Moon Spirit. Zuko later leaves with Iroh on a driftwood raft, as his ship was destroyed in the assassination attempt.
Book 2: Earth
Zuko and Iroh are tricked by Azula, Zuko's younger sister, into thinking that Ozai wants them home, but after the captain of her ship accidentally refers to them as prisoners, they quickly fight her crew and escape. They are then declared traitors of the Fire Nation, and for the first half of the season, Zuko has difficulty living as a fugitive from the Fire Nation and often resorts to theft. Over time, however, he begins to adjust to the situation while being trained in lightning techniques. With Iroh's influence in the secret White Lotus Society, Zuko and Iroh smuggle themselves into Ba Sing Se, start a very successful new life, and manage to open their own tea shop, but Zuko learns of Aang's presence in the city and of the disappearance of Aang's bison. Zuko attempts to continue his search for the Avatar, but Iroh confronts him, convincing Zuko to let Appa go and stop his search. Azula later arrives in the city and captures Zuko with the help of her new allies, the Dai Li, while Iroh escapes. Zuko is put into the Crystal Catacombs with Katara, who initially yells at him but when he reveals more about his life, gradually softens. They are soon rescued by Aang and Iroh, and when Katara and Aang leave, Iroh is captured by the Dai Li and Zuko is manipulated by Azula into betraying Iroh and helping her conquer Ba Sing Se. Following a long battle with Aang and Katara in which the Avatar was fatally wounded, Azula congratulates Zuko and tells him he has restored his honor. Zuko, however, still appears conflicted.
Book 3: Fire
Zuko and Azula return home as war heroes and Zuko's father personally congratulates him for becoming a powerful warrior and staying loyal to his nation. Zuko went to Iroh, who was currently in prison, for advice over his confusion, but Iroh would not talk to him. Not knowing what to do, Zuko sent an assassin after Aang in order to eliminate him. During a trip to Ember Island, he is driven to admit that he is confused to the childhood clique consisting of Mai (now his girlfriend), Ty Lee, and Azula. Following this, Zuko finally talks to Iroh after being sent a note about his great grandfather. He learns he is descended from Avatar Roku and it is his destiny, according to Iroh, to end the war. He takes Iroh's advice and realizes that he can never be the son his father wants him to be and that the war must come to an end. During The Day of Black Sun, he leaves Mai a message in a scroll and expresses regret at leaving her. He then confronts his father, telling him how he felt both about Ozai's treatment of him and the war. He then explains his intentions to free Iroh and join the Avatar. He turns to leave but is baited with knowledge of what happened to his mother, Princess Ursa. After learning she was banished as opposed to dead as he believed, he is attacked with lightning by Ozai at the end of the eclipse, but redirects it and escapes. He attempts to free Iroh, but Iroh has already escaped. Zuko then leaves to join the Avatar.
Zuko arrives at the Western Air Temple and attempts to join the Avatar by pointing out all the good things he's done and that he could teach him Firebending. Aang refuses, and Zuko leaves. Toph, knowing that Zuko was telling the truth, goes to find him in the middle of the night, but she is accidentally burned when Zuko thinks it is someone there to harm him. The next day, Zuko saves Aang and company from the Combustion Man, the assassin Zuko hired to kill Aang. Once Sokka ultimately defeats the Combustion Man, they welcome Zuko into the group, with the exception of Katara who is very reluctant to do so, due to his betrayal at Ba Sing Se. Once Zuko was alone, Katara approached Zuko and darkly warned him that if he harmed Aang or thought of doing so, that she would personally kill him. When Zuko attempts to teach Aang firebending, he finds out that his Firebending skills no longer work. They go to the Sun Warrior Tribe. Here, they find out about the last two dragons, and learn their secrets. He finally finds the true origin of firebending and manages to recover his Firebending skills. During the time Aang and him were searching they seem to begin to treat each other as friends. Unfortunately Zuko still needs to make friends with the other members of the gang.
