Well, it could be about Zuko learning the ways of the dragons. Maybe he discovers hidden dragon lairs and they teach him their ancient fire - bending techniques, which are different from what he's known before.
In many fanfictions where Zuko is adopted by dragons, it often changes his entire character arc. He might gain new powers related to the dragons, like enhanced firebending abilities. For example, he could learn to breathe blue fire, which is a more powerful form of firebending. This adoption could also lead to a change in his relationships. He may become more isolated from the human world as he grows closer to the dragons. His view of the Fire Nation's aggression might also shift as he sees the world from a different, more dragon - like perspective.
The main characters are Harry Potter and Zuko. Harry, a boy with magical powers, would be in a completely different situation being raised by Zuko. Zuko, who has his own story of redemption, would now be responsible for Harry. There might also be other characters from both universes making appearances, like Hermione and Ron from Harry's world, or Aang and Katara from Zuko's world, but Harry and Zuko are the central figures.
It would be really interesting. Zuko has a complex personality. He could teach Harry about perseverance and facing one's inner demons. Harry might learn some unique fighting skills from Zuko's Fire Nation training. Also, Zuko's experience with redemption could influence Harry in dealing with the dark side of the wizarding world.
Well, in many fanfictions, it could be Igneel and another dragon like Metalicana. Igneel is Natsu's adoptive father in the original series, and Metalicana is Gajeel's dragon. Combining them in a fanfiction as Natsu's caretakers could lead to some really interesting character dynamics.
In this fanfiction, they might gain powerful new bending abilities. Zuko could further master his firebending, and Katara could learn unique waterbending techniques from the dragons. Maybe they'd also develop a deeper understanding of each other's cultures and overcome their past differences.
For Zuko, the training might change his view on bending. Instead of seeing it as a tool for power or revenge, he starts to see it as a form of art, like the dragons do. This could make his firebending more refined and less aggressive. For Katara, she could become more confident in her abilities. The dragons' power and wisdom might inspire her to be more creative with her waterbending, perhaps finding new ways to heal or attack.
Eragon would probably have a different view on power. Since he was raised by dragons, he would see power as something to be respected and used sparingly, as dragons do. He may also be more fearless, as dragons are often seen as powerful and fear - inspiring creatures. His communication skills with dragons would be far superior, and he might struggle to communicate as effectively with humans.
Igneel could be one of the main dragons. Since he has a connection with Natsu in the original story, it would make sense for him to be among the dragons raising Natsu. Another could be Metalicana, as he is also a well - known dragon. Grandine might also be there, considering her importance in the Fairy Tail universe.