One key event was when Aang first discovered Yakone's bloodbending crimes. Another was their face - to - face confrontation where Yakone tried to use his bloodbending on Aang. And finally, Aang's victory in the Avatar state.
Katara would likely be shocked and initially angry. She has feelings for Aang and would be hurt by this unexpected turn of events. Zuko, on the other hand, might be conflicted. He wants his sister to be better but this situation is so out of the ordinary. Toph would probably be more straightforward and say what she thinks, which could be a mix of disbelief and amusement.
One idea could be a crossover where Ben 10's Omnitrix malfunctions near Avatar Aang's world. Ben and Aang team up to face a new threat that is causing chaos in both their realms. Maybe some of Ben's alien forms have unexpected interactions with the bending abilities in the Avatar world.
In a fanfiction, the Avatar State of Aang could be used in a more creative way. For example, Aang accidentally enters the Avatar State during a cultural festival. His friends are initially worried, but then they realize that in this state, Aang can communicate with the spirits present at the festival in a unique way. He learns secrets about the spirits and their connection to the human world, which he then uses to strengthen the bond between the two realms when he's out of the Avatar State.
Katara would probably be very worried about Aang, biting her nails and constantly on the edge of her seat. Sokka might be making comments about Aang's fighting style, sometimes joking but also being in awe. Toph would be 'watching' in her own way, feeling the vibrations of the fight and being impressed by Aang's power.
Well, one exciting moment could be when Aang first enters the Avatar State during the fight. It's a powerful display of his connection to the spiritual world. Another might be when he uses a new and unexpected bending move against Ozai, catching everyone off - guard.
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.
Yes, there are quite a few interesting 'Avatar Aang and Katara' fanfictions out there. You can start by looking on popular fanfiction websites like Archive of Our Own. Some fanfictions explore their relationship further after the events of the show, delving into their daily lives and how they grow together.
Another fanfiction could explore the challenges they face during Katara's pregnancy. Since Aang is the Avatar, he has many responsibilities. There could be a conflict where he has to leave for an important mission, but he doesn't want to leave Katara alone. Katara, being strong - willed, tells him to go and fulfill his duties. In his absence, she discovers new water - bending techniques related to pregnancy and childbirth, which she plans to teach other women in their community later.
Aang might go into a deep state of depression. He has always been an emotional character, and having his heart broken by Katara, someone he loves deeply, could send him into a downward spiral. He might isolate himself from his friends and stop practicing his bending for a while.