Often in fanfiction, Peter Pan's character can develop through his interactions with the kids he takes. If one of the kids challenges his leadership or his rules in Neverland, he has to adapt. This could lead to him becoming more open - minded and less autocratic. He may learn from the kids' different perspectives and grow as a character, perhaps even considering the idea of change in a world where he has always been resistant to it.
In some fanfiction, Peter Pan may start to feel a sense of responsibility towards the kids he takes away. He realizes that they are not just playthings but real individuals with their own needs and desires. This makes him more protective of them in a different way than just for the fun of having them in Neverland.
In some fanfiction, the kids that Peter Pan takes away might form a sort of resistance against him. They realize that while Neverland seems fun at first, they miss their real homes and families. So they start planning ways to get back home without angering Peter Pan too much. They might use the magic of Neverland against him in a creative way.
In many Disney Peter Pan fanfictions, Peter Pan does get hurt. Writers may do this to add depth to his character. When he gets hurt, it can lead to different reactions from the other characters in the story, like Wendy taking care of him. It also allows for a different kind of growth in the story. For example, he might become more cautious or learn a valuable lesson about his overconfidence. And it can also create new storylines where the characters have to find a way to heal him, which can be very interesting to read.
His character might develop by learning about the value of friendship outside of the Lost Boys. For example, he could form an unexpected bond with a character from Storybrooke and start to see the world in a different way.
Peter Pan could be developed by showing his struggle with the new emotions and responsibilities that come with adulthood. For example, he might feel guilt for leaving Neverland in the past. He could also be developed through his relationships, like having a more complex friendship with the Lost Boys as an adult.
Peter Pan is likely to be deeply affected. Tinkerbell has always been by his side, so her death might make him feel a great sense of loss. He could become more withdrawn or reckless, as he has lost his faithful companion.
Captain Hook would initially feel victorious. But then he might realize that Peter was an important part of Neverland's balance. Without Peter, the eternal battle that gave his life purpose is gone. He could start to feel lost and even a bit regretful for all the times he tried to kill Peter.
His character might become more impulsive. Since Peter Pan is often about following instincts and having wild adventures, Harry could be more likely to act on impulse rather than think things through carefully like he does in the original series.
The adult story might explore deeper psychological aspects. While the traditional story focuses on the adventures of a boy who doesn't grow up, the adult version could look at how Peter's refusal to grow up affects those around him on a more profound level.
She might develop her character by learning from the different species in Neverland. For example, from the fairies, she could learn about magic and nature; from the pirates, she could learn about cunning and strategy (though not in a negative way). This exposure to diverse personalities would shape her into a well - rounded individual.
Peter Pan's story ends with him staying young and free in Neverland. Wendy goes back to the real world and grows older. It shows the idea that childhood is fleeting and some choose to hold onto it while others must move on.