Well, in some fanfictions, the characters might swap abilities. For example, Naruto could learn how to use the Turtles' weapons while the Turtles could gain some of Naruto's chakra-based powers. This would lead to a lot of character development as they adapt to these new powers in their respective worlds.
Another cool idea in Naruto Ninja Turtles fanfiction is the cultural exchange. The Ninja Turtles, being from a more modern and Western setting, could introduce Naruto to things like pizza and skateboards. Meanwhile, Naruto could show them the traditions and values of the Hidden Leaf Village, creating a really fun and unique story.
One interesting crossover could be a battle between Naruto's ninjutsu and the Turtles' martial arts skills. For example, Naruto could use his Rasengan while the Turtles use their signature weapons and combat moves. Another aspect could be the sharing of knowledge. The Turtles might learn about chakra from Naruto, and Naruto could gain some insights into their street - smart survival tactics in the sewers of New York.
One interesting crossover could be the turtles using their ninja skills to help the Hogwarts students during a big battle at the school. Maybe they teach the students some self - defense moves that wizards don't usually have.
One interesting crossover could be where the Ninja Turtles and Spider - Man team up to fight a common enemy like the Shredder and Green Goblin working together. They could combine their unique skills, with the Turtles' martial arts and the web - slinging and super strength of Spider - Man.
A really cool idea for ninja turtles fanfiction would be to have a story set in a post - apocalyptic New York. The Turtles would have to deal with new threats that emerged after the world as they knew it was destroyed. They might have to face mutated versions of ordinary animals and humans that are far more dangerous. There could also be a sub - plot about the Turtles trying to find other survivors and rebuild some sort of community. This would give a chance to explore their leadership skills and how they adapt to a completely different environment.
One interesting Ninja Turtles fanfic could be about the turtles exploring a new dimension. It might have them facing off against new and strange enemies that they've never encountered before. This would test their skills in different ways and also give the writer a chance to create really unique settings and characters.
Perhaps a fanfiction where the human Ninja Turtles travel back in time to the era when the original turtles were created. They could interact with the mutagen that made the turtles what they are and maybe change the course of their own existence in some way. For example, they could try to prevent certain villains from ever being created.
A crossover with the X - Men could also be cool. Picture the Turtles in the mutant - filled world of the X - Men. They might have to deal with the complex politics of mutants while also facing off against villains like Magneto. The Turtles could learn from the X - Men's experience in dealing with a world that fears and hates mutants, and vice versa.
I'm not really into lemon fanfictions as they often involve inappropriate content. But generally, Ninja Turtles fanfictions can range from adventures that the turtles go on, like facing a new and powerful enemy in the sewers of New York. They might also involve new character relationships and how they interact with the turtles' human friends.
Adult Ninja Turtles stories could involve them mentoring a new generation of heroes. They'd pass on their skills and values, like how to use their weapons effectively and the importance of loyalty. And they might have to make tough decisions about when to reveal their identities to the public in order to gain more support for their cause.
One interesting fanfiction could be about the turtles' adventures in a parallel dimension. Maybe they encounter alternate versions of themselves or face new villains that are unique to that dimension.