What are some interesting ideas for Shadow Hearts fanfiction?

One idea could be a story where the Pokemon trainers are transported to the Kingdom Hearts universe and have to team up with Sora and his friends to fight against the Heartless. They could use their Pokemon's unique abilities in combination with keyblades to defeat the enemies.

One idea could be a crossover where Sora and his friends from Kingdom Hearts end up in the Pokemon world. They could team up with trainers to battle against the Heartless that have somehow invaded the Pokemon realm. Another idea is that some Pokemon could have the power of Keyblades, and they use it to protect their regions from both Pokemon villains and the threats from Kingdom Hearts like Organization XIII. Maybe a Pokemon like Pikachu could befriend Sora and they go on an adventure together to find a way to get Sora back to his own world while also helping the Pokemon world.

One idea could be exploring the backstories of the new characters introduced in Kingdom Hearts 3 in more depth. For example, you could write about how they came to be in the different worlds and what their true motives are.

An interesting Pandora Hearts OC fanfiction idea could be an OC that is a hybrid of a human and a Chain. This OC could struggle with their identity, being neither fully human nor fully a Chain. They could be on a journey to find out where they truly belong. Also, an OC that is a time - traveler who has come to the Pandora Hearts world to prevent a certain catastrophe from happening could make for a great story.

Another interesting concept is an OC who is a member of an organization that opposes Organization XIII in a different way. Maybe they use magic that is not based on darkness or light, but something in between, which causes them to be shunned by both sides at first.

One idea could be a fanfiction where the characters from Kingdom Hearts watch their own adventures from an alternate universe. It would be really cool to see their reactions to different versions of themselves and the events that unfold.

One idea could be a story where Shadow and Tails team up to save a lost ancient technology from a group of villains. They use their unique skills, with Shadow's speed and strength and Tails' intelligence and mechanical aptitude.

One idea could be that the Heartless somehow find their way into the Marvel universe and start attacking various locations. The Avengers, being the protectors, team up with Sora and his friends from Kingdom Hearts. They initially have some clashes due to different fighting styles and ways of understanding the world, but eventually learn from each other and combine their powers to defeat the Heartless. For example, Iron Man could use his technology to analyze the Heartless' weaknesses, while Sora uses his Keyblade to directly combat them.

One idea could be to explore what would happen if Sora and his friends got trapped in Ariel's underwater world during a Heartless attack. They'd have to team up with Ariel and her friends to fight off the Heartless while also dealing with Ursula's schemes in a new way.

Well, some might explore unique character relationships that deviate from the original game's relationships. For example, it could create new storylines where the 'futa' characters interact with male characters in ways that add depth to their personalities and the overall plot.