Katara could be one of the main characters. She might play a role in helping Aang through the process of opening his chakras, either with her healing abilities or just by being there to support him emotionally.
The fanfiction might focus on how opening his chakras changes Aang's relationship with his friends and his role as the Avatar. For example, it could make his connection with the spiritual world stronger, leading to new abilities that he has to learn to control. It could also explore how his friends react to this new, more powerful Aang.
One great Aang fanfic could be one where he has to face an unexpected new threat in the Spirit World. It might explore his growth as the Avatar even further, showing his unique connection to the spirits and how he uses airbending in creative ways to overcome challenges.
One great Aang fanfic is 'Aang's New Adventure'. It takes place right after the end of the series. In this fanfic, Aang has to deal with some leftover Fire Nation rebels who don't want to accept the new peace. It's really exciting as it shows Aang using his bending skills in new and creative ways to bring about peace once again.
Well, physically, a female Aang might have different hairstyles and clothing. Instead of Aang's simple monk robes, she could have a more feminine take on them, like with added ribbons or a different cut. Her hair could be longer and styled in ways that are more typical of female characters in the Avatar world. In terms of her bending style, it might be more graceful. While Aang was fluid, a female Aang could bring an extra level of elegance to her airbending moves.
Another aspect is the relationships in the fanfic. Aang has important relationships with Katara, Sokka, Toph, and others. If a fanfic can develop these relationships in new and interesting ways, it's great. For instance, a story where Aang and Katara have a misunderstanding that they need to work through, which could test their relationship and show their individual growth as characters.
Some fanfictions in this category could focus on Aang's relationships. For example, a story about how Aang helps Toph deal with a family issue that she's been hiding. This would show a different side of Aang, not just as the Avatar but as a true friend. It could also explore how their friendship deepens through this experience.
In the 'Avatar: The Last Airbender' series, there are no real love stories between Azula and Aang. Azula is a complex antagonist, while Aang is the heroic Avatar. Their relationship is mainly one of opposition, with Azula constantly trying to thwart Aang's mission to save the world.
A really interesting fanfic I read had Aang and Katara having a disagreement over how to deal with a new threat. Aang believes in a more peaceful approach, while Katara thinks they need to be more forceful. This creates tension between them, but as they work through it, they realize that they need to combine both their ideas. It's a story that really delves into their characters and how they complement each other.
You can start by looking on popular fanfiction websites like Archive of Our Own or FanFiction.net. Just search for 'Aang not the last airbender' in their search bars and you'll get a list of relevant stories.