One idea could be to explore Rumpelstiltskin's backstory in more depth. Maybe he wasn't always so greedy and his transformation into the tricky character we know was due to some past trauma. For example, he could have been wronged by a powerful figure in his youth, which led him to seek power through his deals.
Another interesting approach is to create an OC (original character) who is a rival spinner to Rumpelstiltskin. This OC could be from a different magical land and have their own set of rules and powers when it comes to spinning straw into gold. They could engage in a spinning competition that has high stakes for both of them.
One idea could be a story where Belle discovers a hidden side of Rumpelstiltskin's past that changes her view of him. Maybe she finds out about a lost love he had before he became the Dark One, and this new knowledge makes her more empathetic towards him.
One idea could be that Emma discovers Rumpelstiltskin has a hidden side that is both alluring and dangerous. Their relationship could start as a power struggle but turn into an unexpected romance. For example, in a situation where they are forced to work together to solve a magical mystery in the Enchanted Forest.
One common theme is power dynamics. Since Rumpelstiltskin is a powerful character in the fairy - tale, when paired with an OC, the story often explores how their different levels of power interact. For example, if the OC is a meek character at first, they might grow in power or learn to navigate around Rumpelstiltskin's power.
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.
One idea could be to explore the Riddler's origin story from the perspective of your original character (OC). Maybe your OC is a detective trying to solve the mystery of the Riddler's first crime spree. Another idea is to have your OC be a sidekick of the Riddler, either willingly or by being forced into it. They could then have a complex relationship where the OC tries to influence the Riddler's actions for better or worse.
One idea could be an OC who is a brilliant scientist in the Fallout world. They could be working on a secret project to reverse the effects of radiation. Another idea is an OC who is a wandering trader, having all kinds of adventures while traveling from one settlement to another, facing raiders and mutants along the way. And a third idea could be an OC that is part of a new faction trying to bring peace and order to the wasteland.
You could also create an OC human who discovers a hidden talent for communicating with trolls through music. In the fanfiction, this character could use their musical ability to bridge the gap between the two worlds, maybe even creating a new form of harmony between trolls and humans that was previously unthinkable.
One idea could be to create a story where your Bratz OC is a new student in Stilesville. She has a unique fashion sense that both confuses and intrigues the other Bratz girls at first. As the story progresses, they become friends and she helps them design a whole new line of clothing for an upcoming fashion show.