Katara: long ago, the four nations lived together in harmony
Roku, who's first mission as the Avatar was trying to get the earthkingdom to leave an island that killed every outsider that set foot on it because his best friend manipulated him into doing it and nearly risked war with both the island and the earthkingdom:
Kyoshi, who had to take down the biggest pirate clan in the world before even knowing she was the avatar, was chased after by someone she considered a friend, and after had to stabilize the earthkingdom from daofei and got involved in fire nation royal family drama:
Kuruk, who had his spirit corrupted and died an early death because of all the dark spirits he had to fight because they were attacking humans:
Yangchen, who had to stop a woman from taking over the entire shang system across four nations and had to face several combustion benders to do it, and also had to make sure the earthking or the chief of the watertribe didn't find out so they wouldn't try to use these people as a weapon, and lost her bison in the process:
