They could travel together. Aang, being the Avatar, may still have duties to different parts of the world. Katara, with her skills and their strong bond, would accompany him. They would use this time to not only help the world recover but also strengthen their relationship as they face new challenges and adventures in different lands.
One possible storyline could be them traveling the world together to help rebuild the nations. They could use Aang's Avatar powers and Katara's waterbending skills to bring water to drought - stricken areas or help with construction using earthbending - like techniques. Another could be them settling down in the Southern Water Tribe and starting a family while also teaching the next generation about the importance of the four nations' unity.
Their relationship could deepen as they share in the joys and sorrows of rebuilding the world. They've been through a lot during the war, and now they can truly rely on each other. They might become even closer friends at first, with a mutual respect for each other's abilities growing stronger.
In some cases, the anger could be a catalyst for a more romantic development. Aang expressing his strong emotions might make Katara realize the depth of his feelings for her. Or it could be the other way around, Katara's reaction to his anger could make Aang see her in a new light, leading to a shift in their relationship dynamic towards a more romantic one.
Aang would contribute to the post - war world in fanfiction by teaching the values of the Air Nomads, like non - violence and respect for all life. This would influence the new generation. Katara, being a powerful waterbender, could help with environmental restoration. For example, she could use her waterbending to clean polluted water sources. They would also be involved in diplomatic efforts, as aang's connection to the spirit world and Katara's wisdom would make them great mediators between different groups. Their relationship would also inspire others to work towards a united world.
In fanfiction, they might start off as friends who gradually realize their deeper feelings for each other. They could bond over their shared experiences during and after the war, such as the rebuilding of the wizarding world. This new world would be different from what they knew before, and they could find comfort in each other's company while adapting to the changes.
Their relationship would likely deepen. After the war, they have more time to focus on each other. They'd probably have more romantic moments, like taking walks on the beach or having quiet dinners together. Aang would be more open about his feelings, and Katara would be more affectionate towards him.
Perhaps Aang has a vision of the future where Katara is happier without him. So, in the fanfiction, he decides to respect that future and let her go.
Well, a common theme in fanfiction is their romantic adventures. Fanfic writers love to imagine Aang and Katara going on secret dates to beautiful, hidden places. These could be secluded islands or magical caves. Their relationship in fanfiction can also be a bit more complex than in the original series. There could be misunderstandings due to their different upbringings. Aang being the last Airbender with a more carefree nature at times, and Katara being a strong - willed Water Tribe girl.
In fanfiction, they might have a peaceful life. Aang could focus on rebuilding the Air Nomad culture. Katara would be by his side, using her waterbending skills to help the new communities. They could also start a family, passing on their bending knowledge to the next generation.
It could also be that Katara was being overly critical of Aang's progress in learning new skills. Aang might feel frustrated and angry if Katara is constantly pointing out his flaws instead of being more encouraging, especially if he's already trying his best.