You could do a crossover with a superhero universe, like the Marvel Universe. The turtles could cross paths with Spider - Man. Picture them swinging through the city together, with the turtles using their ninja skills and Spider - Man using his webs. They'd have to figure out how to combine their fighting styles to take on a villain like Doctor Octopus who has some mutagen - related experiment going on.
A 'rottmnt crossover fanfiction' could involve crossing over with the 'Teenage Mutant Ninja Turtles' from different versions. Maybe the Rise of the TMNT turtles meet the 1987 turtles. They could have a friendly sparring match at first to compare their skills, and then work together to stop an ancient evil that has been awakened in both their dimensions.
One interesting idea could be a crossover with "Moana". Elsa's ice powers and Moana's connection to the ocean could create a really cool dynamic. Maybe Elsa accidentally freezes part of Moana's ocean and they have to work together to fix it. Another could be with "Tangled". Rapunzel's long hair and her adventurous spirit combined with Elsa and Anna's journey in Frozen 2 would be exciting. Rapunzel could use her hair to help them climb mountains or cross chasms. A third idea is a crossover with "Beauty and the Beast". Belle's love for books and knowledge could help Elsa understand more about her powers and the history of magic in the Frozen world.
A great 'rottmnt crossover fanfic' has well - written characters. It should stay true to the original personalities of the 'rottmnt' characters while also adapting them to fit into the new crossover universe. For example, if they cross over with a magical world, their reactions and how they use their skills should be believable.
Begin by brainstorming characters from both the 'rottmnt' and the other franchise you want to cross over with. If it's 'Star Wars', think about how the Turtles would fit into the Star Wars universe. Are they Jedi - like ninjas? Create a character sheet for each important character. Then, outline the story. Have a clear beginning, middle, and end. The beginning could introduce the problem, like the Turtles being accidentally transported to a Star Wars planet and having to find their way back while getting involved in a local conflict.
A Rambo crossover fanfiction could involve him crossing over into the Star Wars universe. Rambo's guerilla warfare tactics could be interesting in a galaxy far, far away. Maybe he helps the Rebel Alliance in a ground - based battle against the Empire. Or a crossover with the Predator series. Rambo would be a worthy opponent for the Predator, and the fight between them in the jungle could be epic. Also, a Rambo and John Wick crossover would be intense, two highly skilled fighters on the same side or perhaps initially at odds.
One idea could be a crossover with a modern military setting. The Decepticons could be trying to steal advanced military technology. Another is a crossover with a post - apocalyptic world where they are competing with other factions for resources. A third could be a crossover with a magical realm, with the Decepticons trying to harness the magic for their own evil purposes.
One idea could be a crossover with Naruto. Kakuzu could be sent to the Naruto universe and form an unlikely alliance with a shinobi village to fight a common enemy, like the Akatsuki from his own world turned rogue in the new universe. This would create a lot of interesting character dynamics and battles.
Another option is a crossover with 'The Little Mermaid'. The characters from the descendants could meet Ariel and her friends underwater. Evie might be interested in the mermaid fashion and could design new outfits inspired by the underwater world.
Another possibility is a crossover with the world of Naruto. The characters from MHA could participate in the Chunin Exams. Bakugo might be really into showing off his skills in this new and different kind of competition.
One idea could be a Venom crossover with Spider - Man in an alternate universe where they have to team up against a common enemy like Carnage. Another could be a Venom and Deadpool crossover, with their crazy personalities clashing and then somehow working together. Maybe a Venom crossover with the X - Men, where Venom's alien nature causes some interesting reactions among the mutants.
For a Monokuma crossover fanfiction, consider a crossover with 'Final Fantasy'. Monokuma could be a summoned monster by an evil villain in the game's world, causing all sorts of problems for the heroes. He might even try to take over the crystals. A crossover with 'Persona' could also be interesting. Monokuma could enter the Metaverse and start his own 'Palace', recruiting Shadows to enforce his rules. And how about a crossover with 'One Piece'? Monokuma could be a new Warlord of the Sea, using his wacky yet dangerous devices on the Straw Hat Pirates and their allies.