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.
Aang might become more confident. After the war, he has proven himself as the Avatar and might be more self - assured in his decisions. Katara could become more diplomatic. With the experience of the war and seeing different cultures interact, she may use her skills to help resolve disputes between tribes or nations.
Their family could start a new school that combines airbending and waterbending teachings. This would allow for new techniques to be developed as students learn from both disciplines. It could also promote better understanding and cooperation between airbenders and waterbenders.
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.
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.
Katara could be heartbroken. She might initially be in denial, not believing that Aang has actually left. Then she could become angry, feeling betrayed by Aang's sudden departure.
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.
They would respect each other's cultures. Aang would learn more about the water tribe's way of life, like their fishing techniques and family values. Katara would also embrace the air nomad culture, perhaps learning their meditation techniques. They would celebrate both cultures' holidays and teach their children about the importance of both.
Toph would be blunt about it. She might tell both Aang and Katara that they're being stupid if she thinks the break - up is over something silly. But if it's a more serious issue, she'd support them in her own way. She might offer a place for Katara to stay if she needs to get away from Aang, or she might give Aang some tough - love advice on how to handle the situation.
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 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.