In the series "Avatar: The Last Airbender," the concept of destiny and fate is explored through the characters' journeys and the overarching theme of balance in the world. The characters, especially Aang, struggle with fulfilling their destinies as the Avatar and the roles they are meant to play in restoring balance to the world. Additionally, the series delves into the idea of individual agency and choice in determining one's fate, highlighting that while destinies may be predetermined, how one chooses to act and make decisions can ultimately shape their own path. Throughout the series, characters grapple with the idea of destiny, fate, and free will, offering a complex exploration of these concepts within the context of a richly developed fantasy world.