Well, the theme of family also often comes up. Zuko's family situation is complicated, and Mai is also affected by her family's expectations. Fanfics may explore how their relationship is influenced by their families. For example, how Zuko's relationship with his father affects his relationship with Mai. Also, the theme of growth is common. Both Zuko and Mai grow as characters in fanfics, learning more about themselves and each other.
Well, 'Zuko and Mai: A New Beginning' is a really good fanfic. It starts right after the end of the series and shows Zuko and Mai trying to rebuild their relationship. It has some really sweet moments between them. There are also fanfics that explore what would have happened if Mai had been more involved in Zuko's journey earlier, like 'Early Encounters: Zuko and Mai', which is an interesting take on their relationship.
Avatar: The Last Airbender is indeed an original story. It has its own distinct style and narrative that sets it apart. The combination of elements like bending powers, diverse characters, and complex story arcs make it a one-of-a-kind creation.
Definitely not real. It's a fantasy world crafted with unique characters and magical elements that exist only in the realm of imagination and storytelling.