Who could be the main antagonist in a 'Peter Pan grows up fanfiction'?

It could also be a new character, perhaps a dark sorcerer who is jealous of the magic in Neverland. This sorcerer might target Emma because she has an unknown power within her that could disrupt his own plans for the magical world. He would try to separate her from Peter Pan and use her power for his own evil deeds.

Captain Hook would be an obvious choice. His hatred for Peter Pan could extend to Moira when she becomes Peter's friend. He might see her as another obstacle in his quest to get revenge on Peter.

Perhaps an older, forgotten enemy of the Lost Boys could resurface. Maybe someone from their past in Neverland who they thought was defeated but has now returned with a vengeance. This could be a character who was once a Lost Boy himself but turned bad due to some dark influence in Neverland.

A group of bandits might be the main antagonists. They see Percy as someone they can easily rob or enslave since he is all alone. Percy would then have to use his skills to outwit them.

Perhaps a new student named Tiger Lily. She comes to the high school and has her own set of rules and ideas. She wants to take over Peter's group of friends and tries to drive a wedge between Peter and Wendy. She's very competitive and sees Wendy as an obstacle to getting closer to Peter.

Well, it could start with Peter Pan having a strange encounter in Neverland that makes him start to age. As he grows up, he has to deal with new emotions like love in a more grown - up way. He might fall in love with a new character, maybe a girl who has washed up on the island. His relationship with Captain Hook could also change. Instead of just being enemies, they could become reluctant allies as they face new threats to Neverland that only a more mature Peter can understand.

It could be the Green Goblin. Since Harry has a connection to the Green Goblin in the original story, it would be interesting if the Green Goblin resurfaces in a new and more powerful form. Peter and Harry would have to put aside their differences and past traumas related to the Green Goblin to team up and defeat this common enemy.

It could be a jealous demigod who sees Percy's wings as an unfair advantage. This character might try to find a way to cut off Percy's wings or steal the power that gave him the wings.

It could be a new dark wizard who targets Harry because of his fame. This wizard might be jealous of Harry's status as the hero who defeated Voldemort and wants to prove himself as more powerful.

The mermaids could be the main antagonists. They are known to be jealous and territorial in the Peter Pan stories. If the lost girl catches Peter Pan's attention in a way they don't like, they could make her life in Neverland miserable. They might use their alluring voices and their knowledge of the waters around Neverland to try and drive her away or lead her into danger.