During their stay on Ember Island, Azula noticed several teenagers playing a game of kuai ball. She immediately commanded Ty Lee, Zuko, and Mai to gather around, demanding they play next. Azula used her tactical insight to devise a game plan that involved using the weakness of one of their opponents, an old injury, against her. Utilizing their acrobatic skills, they managed to quickly defeat the opposing team, destroying the playing field and net in the process.
The court for a kuai ball game consists of a circular playing area divided by a net. The object of the game is to hurl the ball over the net using one's hands or feet, with points being scored by having the ball hit the ground on the opposing team's side of the net. The game ends when one team reaches ten points.
Firebenders and acrobats have an advantage, as the game requires moving the legs and the rest of the body quickly, in a similar fashion to firebending.
Kuai ball appears to be based on sepak takraw, a Southeast Asian sport similar in concept to volleyball but played without the use of hands, though played on sand.
- In the commentaries, the creators stated they later learned from a production artist that there was a Korean sport that was either similar to or exactly like kuai ball,[source?] namely sepak takraw.