Aang was a male Air Nomad, the immediate successor of AvatarRoku, and the predecessor of Avatar Korra. He was fun-loving, somewhat naive and adventurous. He already seemed to have a conscience against killing people, as he saved Zuko from falling from a giant statue, saving him from a possible death. He already had some waterbending experience, as he bent the water and both corrected Kya's attempts and gave her advice.
Aang and his friends, Kya and Sokka, were fleeing from Prince Zuko, who was hunting them down from his ship. They ran into a sea serpent, but it took interest in the ship after Zuko attacked it, allowing the trio to escape to an island. While there, Kya practiced her waterbending, but could not control it well; Aang offered her some advice and demonstrated the correct leg stance. When Sokka demanded they help search for food, Kya was reluctant to leave Aang, as "the world's last hope", and so Sokka went off alone in a huff. Kya and Aang remained at the camp and engaged in a slightly awkward conversation before Momo alerted them of an upcoming danger.
When they reached the Fire Nation base and saw Sokka being taken in, Kya decided to go after him, but told Aang to stay hidden. She became captured as well, but refused to reveal Aang's whereabouts. When Aang flew in, shocking everyone, the soldiers threw Sokka and her into a pit. Aang sat on the scaffolding, evading Zuko's attacks while Momo distracted the soldiers and then engaged Zuko's pet hawk in a flying duel of sorts.
As the scaffolding disintegrated, Aang and Zuko moved their fight to the defaced Avatar statue. When Aang was almost cornered by Zuko, he simply threw himself off the statue, setting him in danger and thus activating the Avatar State, and blowing Zuko off. Coming out of the Avatar State, Aang caught an unconscious Zuko, but dropped him a short distance into a wall to fly over to Kya and Sokka and subsequently escape.