In a Naruto, Kyuubi and Rosario Vampire fanfiction, there could be a plot where a character from Rosario Vampire travels to the Naruto world and discovers the legend of the Kyuubi. This character could then try to bring the power of the Kyuubi back to their own world, creating a whole new set of adventures and challenges as they deal with the different cultures and powers in both worlds.
One interesting crossover could be the combination of Naruto's ninja skills with the supernatural elements of Rosario Vampire. For example, Naruto could use his shadow clone jutsu in the Rosario Vampire world, where he has to deal with vampires, werewolves and other monsters. The clones could be used to distract the enemies while he figures out their weaknesses. Another crossover aspect could be the sharing of power - like if some of the Rosario Vampire characters were to learn chakra control from Naruto. This would create a whole new dynamic in battles and relationships within the fanfiction world.
One idea could be that Naruto, with the power of the Kyuubi, somehow ends up in the Rosario Vampire world. He could use his ninja skills and the Kyuubi's chakra to face the various supernatural threats in that world. Maybe he teams up with Tsukune and the other characters to protect the school from an even greater evil.
One possible interesting crossover could be having Luffy from One Piece end up on the Rosario Vampire campus. His carefree and fearless attitude would surely stir things up among the various supernatural beings there. He might mistake some of the vampire or monster students for strange new island inhabitants and try to befriend them in his usual enthusiastic way.
One of the most interesting crossovers is when the female characters from both series interact. For example, Integra from Hellsing and Moka from Rosario Vampire. Integra's strong leadership and no - nonsense attitude combined with Moka's more innocent yet powerful vampire side can create some really unique and unexpected storylines.
One of the most interesting crossovers is when they blend the powers. For instance, in some fanfics, the characters from Rosario Vampire gain some of Venom's symbiotic abilities, which makes for some really cool fight scenes. It's fascinating to see Moka with Venom - like powers, for example.
One interesting fanfiction could be where Naruto, with his Kyuubi powers, somehow gets involved in the world of Rosario Vampire. Maybe he's on a mission and stumbles upon the school. It could be a story full of action and unique character interactions.
A possible crossover idea is the characters from Harry Potter attending the Youkai Academy from Rosario Vampire. Imagine Harry, Ron, and Hermione trying to blend in with vampires, werewolves, and other supernatural beings. There could be a lot of humorous situations as they try to adapt to the different rules and cultures of the academy.
A cool plot for a Rosario Vampire crossovers fanfic could be a time - travel scenario. The characters go back in time to the era when vampires were first created. They could meet the original vampire lords and learn about the true origins of their kind. This could also lead to a conflict as they might accidentally change the course of vampire history. Or perhaps there could be a crossover with a magical girl series. The Rosario Vampire girls could learn some new magical powers from the magical girls and use them to fight off a new threat that is immune to their normal vampire and monster abilities.
Naruto could be a new student at the Yokai Academy. His presence with the Kyuubi's power would disrupt the balance. For example, the vampires might see him as a threat or a potential ally. He could use his shadow clones to spy on different factions, like the witches or werewolves, to understand the politics of the school better.
The plot might involve a threat that endangers both Naruto's world and the world of Rosario Vampire. Naruto, with his Kyuubi - enhanced abilities, teams up with the vampires and other creatures in Rosario Vampire. They'd have to combine their different powers, like Naruto's Rasengan and the vampires' super strength, to fight against the common enemy. It would be a wild mix of ninja action and vampire drama.