Avatar_legend about Aang.

Main characters
Aang is the last airbender and the Avatar. Kind and cheerful, he must master all four elements and stop the war.
Katara is a talented waterbender who is caring and brave.
Sokka is Katara's brother, he does not possess magic, but is an excellent warrior and strategist.
Toph Beifong is a blind girl, the most powerful earthbender, who created metalbending.
Zuko is the prince of the Fire Nation. He initially hunts Aang, but later becomes his friend and firebending teacher.
Appa is a flying bison and Aang's loyal friend.
Momo is a flying lemur and the team's favorite.

Fire Nation:
Iroh is Zuko's wise uncle, a former general and firebending master.
Ozai is the Fire Lord and the main villain of the series.
Azula is Zuko's sister and a very powerful fire and lightning bender.
Mai is Azula's friend and a knife thrower.
Ty Lee is Azula's friend and can block magic by hitting specific points on her body.
Admiral Zhao - Fleet commander, Aang's enemy

Allies:
Suki is the leader of the Kyoshi warriors and later helps the team.
King Bumi is an old friend of Aang and a powerful earthbender.
Jet is a fighter against the Fire Nation who sometimes makes bad decisions.
Haru is a young earthbender.
Theo is a boy inventor and a friend of the team.

Kingdom of Earth
Long Feng is the secret ruler of Ba Sing Se and one of the main villains.
King Kuei is the ruler of Ba Sing Se.
Spirits and past Avatars
Avatar Roku is the previous Avatar and helps Aang with advice.
Avatar Kyoshi is a legendary and very powerful Avatar.
Koh the Face Stealer is a dangerous spirit that takes the faces of those who show emotion.
Tui and La are the spirits of the Moon and the Ocean.
Other important characters
Princess Yue, the princess of the Northern Water Tribe, saves Luna.
Pakku is a great master of water magic.
Piandao is a sword master who trains Sokka.
Jin is a girl from the Earth Kingdom who is friends with Zuko.