A great idea for Marvel OC fanfiction is an OC who is a descendent of an ancient and forgotten race in the Marvel universe. This OC discovers their heritage and realizes they have a special connection to a powerful artifact. They then have to decide whether to use this power for good or be tempted by the darker forces that also seek the artifact. As they journey through the Marvel world, they meet various heroes and villains who all have their own agendas regarding the artifact.
Well, you could write a fanfiction about a Marvel OC who is from an alternate dimension where the roles of heroes and villains are reversed. This OC comes to the main Marvel universe to try and right the wrongs in their own dimension. Or perhaps an OC who is a young Asgardian with a gift for magic that Odin tries to keep hidden for some reason, and the OC has to navigate the politics of Asgard while also dealing with their emerging powers.
Maybe the OC is a scientist who accidentally creates a device that links him to the minds of the female Marvel characters. This leads to a series of comical and heart - warming interactions as they get to know each other on a deeper level. For example, he might initially be confused by their different personalities but then starts to fall for them one by one.
You could write a fanfiction where some of the Eternals get separated from the group and have to survive on their own in a hostile part of the world. They would have to use their powers in new and creative ways to stay alive and find their way back to the others. This would show their individual strengths and weaknesses more clearly.
A great marvel crossovers fanfiction idea is to cross over the Guardians of the Galaxy with the Fantastic Four. The Guardians' intergalactic adventures meeting the scientific minds of the Fantastic Four would be full of potential. You could have Rocket Raccoon and Mister Fantastic sharing their tech knowledge, or Groot and The Thing having a friendly brawl. It would be a fun mix of different universes within the Marvel world.
One idea could be exploring an alternate universe where the villains become heroes. For example, Loki could be a champion of Asgard, using his trickery for good. Another is to focus on the backstories of minor characters, like how a S.H.I.E.L.D. agent got recruited. You could also write a fanfic about a team - up that never happened in the official comics, such as Spider - Man and Doctor Strange working together to solve a magical mystery.
One idea could be a crossover between the X - Men and the Avengers. Imagine Wolverine teaming up with Captain America in a battle against a common enemy like Ultron. Another could be a Spider - Man and Doctor Strange crossover, where Spider - Man's quick thinking and agility combine with Doctor Strange's magic to solve a multiverse - level threat.
One idea could be exploring what would happen if a hero from the Marvel universe was wrongly accused of a crime in the Injustice world. For example, Spider - Man being framed for a mass destruction event. Another could be a story about how the X - Men would deal with the unjust laws in the Injustice setting. Maybe they would form an alliance with some of the Injustice heroes to fight for mutant rights within that corrupted system.
Another interesting concept is a story where Percy Jackson is somehow transported to the Marvel universe. He could use his water - controlling powers in unique ways there. Maybe he'd join forces with Namor, the Sub - Mariner, and they'd have an underwater adventure together, facing off against some underwater threat that only their combined powers could handle.
In'marvel meets dc fanfiction', a great concept is the love story between Wonder Woman and Thor. They are both powerful warriors from different mythologies. Their relationship could bring about a new dynamic, like how they combine their powers. Also, the Flash and Quicksilver racing each other would be an exciting scenario. It would test their speed limits and show off their unique abilities in a competitive way.
One idea could be that Batman finds himself in the Marvel universe due to a strange multiverse rift. He teams up with Iron Man to stop a tech - based villain who is stealing advanced technology from both their worlds. Another could be Batman and Spider - Man working together in Gotham. Spider - Man's acrobatics and sense would be a great addition to Batman's detective skills.
A cool dc marvel crossover fanfiction might involve Batman and Iron Man. Picture Batman being intrigued by Iron Man's high - tech gadgets and the two of them collaborating to create an even more advanced piece of technology to defeat a new breed of super - criminals that are using alien and advanced Earth - based tech.