An interesting Precure OC fanfiction idea could be an OC who is an outcast in the Precure world at first. Maybe they don't have the typical 'cute' appearance of a Precure but possess extremely powerful magic. They struggle to be accepted by the other Precures but eventually prove their worth. Another idea is an OC who is a detective - like Precure. This OC could use their intelligence and deductive skills to figure out the plans of the villains. And a third idea could be an OC who has the power of transformation not just in appearance but also in personality, depending on the situation they are in during battles.
One idea could be creating an OC who has the power of music in the Precure world. They could use melodies to heal and fight against the villains. Another is an OC from a different dimension who stumbles into the Precure universe and has to learn their ways to help. And also, an OC that is a hybrid of a magical creature and a human in the Precure world, bringing unique powers and a fresh perspective to the story.
One idea could be an OC who has the power of music in the Precure world. She could use melodies to heal or empower others. Another idea is an OC from a different dimension who comes to the Precure world with unique powers and has to learn how to fit in and fight alongside the Precure. Maybe an OC that is half - human, half - magical creature and has to hide her true identity while being a Precure.
One idea could be a crossover with another magical girl series like Sailor Moon. The Smile Precure girls could meet the Sailor Scouts and they team up to fight a common enemy that threatens both their worlds. Maybe they have to combine their powers in new and unexpected ways.
A great plot could be that the Precures lose their memories but still feel a strong urge to fight evil. They would have to figure out who they are and what their powers are while still protecting the world. Or, you could write a fanfiction where a new villain emerges who can control the stars in a different way than the previous ones. This would force the Precures to come up with new strategies to defeat the villain.
A time - travel plot in a Precure All Stars fanfic could be really cool. Maybe the Precure travel back in time to the origin of their powers and have to make sure that the events that led to their powers being created happen correctly. It could involve meeting their predecessors and learning about the true nature of their powers.
One popular idea is an alternate universe where the Precure characters have different powers or backstories. For example, they could be in a steampunk world. Another idea is a crossover with other popular magical girl series. This can bring new and interesting dynamics. Also, a fanfic about the Precure's daily lives outside of their heroic duties, like going to school or dealing with family, can be quite engaging.
A great crossover aspect could be the Precure's magic interacting with the Warhammer magic or technology. The Precure's spells could have unexpected effects when used in the Warhammer setting. Maybe their purification magic could be used to cleanse some of the corrupted areas or creatures. And they could also learn from the Warhammer characters, like how to better defend against certain types of attacks in this dangerous universe.
One interesting Precure All Stars fanfiction could be about all the Precure characters from different series coming together to face a super - powerful villain that was created by combining the powers of all their past enemies. This would be a great story as it showcases the unity and combined strength of the Precure girls.
One idea could be creating an OC who has a unique power related to time manipulation. They could be from a different dimension and end up in the Avengers' world. Another idea is an OC who is a master of ancient magic and teams up with Doctor Strange within the Avengers group. Maybe an OC that is a super - intelligent android created by a villain but has a change of heart and joins the Avengers.
You could create an OC for your Persona OC fanfiction who is an artist. This artist OC could use their art as a way to understand and even manipulate the Metaverse. For example, they might draw scenes from the Metaverse that give clues about upcoming events or hidden locations. Their art could also be a form of therapy for other characters who are struggling with their dual lives in the real world and the Metaverse.
Perhaps an OC who is a half - human, half - beast creature. This OC could struggle with acceptance in both the human and beast - kin societies. They end up meeting the main characters during their adventures and learn to embrace their unique identity with the help of the group, while also adding their own combat skills, which are a blend of human strategy and beast - like strength, to the team.