The theme of exploring new bending abilities also exists in fan fictions. Writers often come up with new ways of bending or combinations of elements. It could be a character who can bend two elements at once in a unique way. This adds a whole new layer of excitement and creativity to the Avatar universe.
Another theme is character relationships. There are a lot of fan fictions that focus on the relationship between Katara and Aang, or Zuko and Iroh. They might explore things like their backstories together or how their relationships could have developed differently. For instance, some fan fictions might show a more complex relationship between Zuko and his father, exploring the possibility of redemption from a different angle.
One common theme is 'what if' scenarios. For example, 'What if Aang hadn't been frozen?' These types of fan fictions explore different paths the story could have taken. It's really interesting to see how the whole Avatar world would be different.