Avatar: The Last Airbender - Season 3 - Eps 21: Sozin's Comet: Avatar Aang (4)
Aang defeats the Fire Lord by bending the elements within the Fire Lord and removing his firebending abilities. After Zuko is taken down protecting Katara from Azula, Katara joins the fight and manages to restrain Azula. Afterwards, Zuko is crowned Fire Lord and promises a better future for the world, while Aang takes his place as the next Avatar. Katara finally shows her love for Aang as they kiss under the setting sun.
About Avatar: The Last Airbender

Title: Avatar: The Last Airbender
First Air Date: 2005-02-21
Last Air Date: 2008-07-19
Status: Ended
Rating: 8.74/10 (from 4264 votes)
Language: EN
Seasons: 4
Total Episodes: 61
Network: Nickelodeon
Genres: Animation, Action & Adventure, Sci-Fi & Fantasy
Production Companies: Nickelodeon Animation Studio, JM Animation, DR Movie, Moi Animation, Nickelodeon Productions
Synopsis
In a war-torn world of elemental magic, a young boy reawakens to undertake a dangerous mystic quest to fulfill his destiny as the Avatar, and bring peace to the world.
Cast

Zach Tyler Eisen
Aang (voice)

Mae Whitman
Katara (voice)

Jack De Sena
Sokka (voice)

Dante Basco
Zuko (voice)

Jessie Flower
Toph Beifong (voice)

Greg Baldwin
Iroh (voice)

Dee Bradley Baker
Appa / Momo (voice)

Grey DeLisle
Azula (voice)

Cricket Leigh
Mai (voice)

Olivia Hack
Ty Lee (voice)