A new character could be the main character. A young orphan who discovers they have some sort of magical ability in the 'Once Upon a Time' realm. Their soul is broken from the loneliness and abandonment. But they use their new - found powers to reach out to the lonely and broken - hearted characters in the story, mending their hearts and in turn, healing their own soul.
Perhaps the main plot focuses on a hero who has his soul shattered after a great battle against an evil force in the 'Once Upon a Time' world. He then sets out on a journey to mend the hearts of those who have been affected by the evil, including his own comrades and the innocent villagers. Along the way, he discovers that by mending their hearts, his broken soul begins to heal. It could involve him using his courage and new - found wisdom to face the traumas of the past and create a more positive future for everyone.
It could be a young wizard. Wizards are often main characters in fairy tales. They can use magic to solve problems and have exciting adventures.
Maybe a half - zombie, half - human hybrid. They would have the unique ability to understand both sides, the zombie side from their undead nature and the human side from their living part. This would make for an interesting internal conflict as well as a great way to explore the relationship between the two species in the novel.
A curious child might be the main character. This child is always exploring Troy St and finding new things that others overlook.
Sora would be really interesting. He has such an innocent and determined nature in 'Kingdom Hearts'. In the 'Once Upon a Time' setting, he could be the one to bring a sense of hope and adventure. His reactions to the different fairy - tale characters and settings would be fun to explore.
A new character could be the main character as well. This new character could be a human who is suddenly thrust into the vampire world in a 'once upon a time' way. They could be the one to bring a fresh perspective to the story, seeing the vampires and their lore from an outsider's point of view and having to learn quickly to survive.
Sora and Henry. Henry is always looking for adventure and has a connection to the storybook world. Sora could show him more about different worlds and how to fight using the Keyblade. They could form a really cool mentor - mentee relationship.
A character like Hook could be an interesting choice. He has his own complex past and a bit of a rogue nature. Pairing him with Drizella could lead to some interesting power plays and character development. They could either become allies in some devious scheme or Hook could end up being the one to make Drizella see the error of her ways.
A really popular one is 'Heart of the Enchanted Forest'. This fanfic delves deep into how the Heartless could potentially invade the Enchanted Forest from Once Upon a Time. It has some great action scenes with characters from Kingdom Hearts fighting alongside the heroes of Once Upon a Time. For example, Riku teams up with Prince Charming to battle a horde of Heartless that are threatening the forest.
A curious child might be the main character. They find the broken lamp in their grandparents' house and start to imagine all sorts of stories about it. They might try to fix it with their limited tools and knowledge, getting into all sorts of cute and innocent mishaps along the way.