Well, you could focus on a superhero oc that is an outcast in the superhero community because their power is considered too dangerous or uncontrollable, like the power to create black holes on a small scale. But they learn to master it and prove their worth. Or, make a story about a young superhero oc who inherits their powers from a long - lost relative who was a great hero in the past and has to live up to that legacy.
A great concept for superhero oc fanfiction is a hero who has the power of empathy. They can sense the emotions of others and use that to either calm down villains or boost the morale of their fellow superheroes. Also, you could write about a superhero oc from another dimension who comes to our world with powers that are completely alien to our understanding, like the ability to turn into a living energy form.
Here are some ideas. A group of students from the superhero academy could be stranded on a strange planet during a field trip. They have to use their powers in new and creative ways to survive and find a way back home. Or perhaps there's a prophecy about a'special one' among the students who will bring either great glory or destruction to the academy. This leads to a lot of tension and mystery as everyone tries to figure out who it could be.
Well, you could write a fanfic where Ladybug and Chat Noir get transported to an alternate universe. In this universe, their roles are reversed, and they have to figure out how to get back to their own world while dealing with the differences. Also, a plot could revolve around a Miraculous that has been lost for centuries suddenly resurfacing, and all the chaos and mystery that comes with it. Maybe a story about Ladybug having to deal with a personal crisis that affects her superhero duties, like losing her confidence after a major defeat.
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.
One idea could be creating an OC who is a transfer student with a unique past related to the Dark Hour. For example, they might have had a family member affected by Shadows long before coming to the school. Another idea is an OC with a special ability that doesn't quite fit the normal Persona - using skills that are more about mental manipulation rather than direct combat. And you could also have an OC who is initially a skeptic about the whole Persona thing but slowly gets drawn into it.