Perhaps Naruto gets lost during a time - space ninjutsu gone wrong and ends up at Hotel Transylvania. The vampires and other monsters initially see him as a threat but then realize he can be an ally. He could teach some of the younger monsters ninjutsu in exchange for their help in finding his way back home. And there could be a big showdown where Naruto uses his Rasengan against some powerful dark force that is threatening the hotel.
In a fanfiction, Naruto could be invited to Hotel Transylvania as a special guest. He is known for his powerful chakra which the hotel residents are interested in. Dracula might think Naruto's chakra can be used to power some ancient magic device in the hotel that has been dormant for years. But things go wrong when a rival vampire tries to steal Naruto's chakra for his own evil plans and Naruto has to fight to protect himself and the hotel.
One idea could be that Naruto is on a mission in a world similar to that of Hotel Transylvania. He could encounter the unique creatures there and have to team up with some of the hotel residents, like Dracula, to defeat a common enemy. Maybe an evil ninja has found a way to drain the life force of the supernatural beings in the hotel and Naruto's skills are needed to stop it.
One idea could be that Naruto, with his godlike powers, accidentally ends up in the Hotel Transylvania universe. He could befriend the monsters there and use his powers to help them with some kind of threat that they are facing, like a powerful enemy who wants to destroy the hotel and the peace between humans and monsters. His shadow clone jutsu could be used in creative ways, like having clones help with the hotel's daily tasks while he goes on adventures with Dracula's daughter.
A third idea could be a crossover where there is a big tournament. Characters from both Naruto and Hotel Transylvania participate. Naruto and his friends use their ninja techniques, and the monsters from Hotel Transylvania use their supernatural abilities. It would be an exciting and unique battle where the two different worlds' combat styles collide.
Another fanfiction could involve a spell gone wrong in the Harry Potter universe that transports some of the Hogwarts students to Hotel Transylvania. The students then have to adapt to this new and strange place, and they could teach the vampires and other creatures about magic from their world, while also learning about the unique abilities of the hotel's inhabitants. For example, the werewolves in Hotel Transylvania could compare their transformation experiences with those of the werewolves in the Harry Potter world.
One idea could be that Jonathan discovers a hidden vampire power within himself. Maybe he starts to have visions of ancient vampire battles and uses this knowledge to help Dracula and his friends in a new crisis at the hotel. For example, he could foresee an attack from a group of vampire hunters and use his unique human - vampire hybrid perspective to come up with a clever defense strategy.
One idea could be Naruto somehow gets transported to the world of Hotel Transylvania 2. He could use his ninja skills to help Dracula protect the hotel from new threats. Maybe he teaches the vampire kids some cool ninja moves in exchange for learning about vampire powers.
It could be really interesting. Picture Drac from Hotel Transylvania sending his daughter Mavis to Hogwarts. The magical creatures in the Harry Potter world could interact with the spooky but friendly monsters from Hotel Transylvania. For example, Hagrid might befriend Frankenstein's monster. And the spells in Harry Potter could be used in the Hotel Transylvania setting, like using Lumos to light up the dark corridors of the hotel.
Dracula and Naruto would be an interesting pair. Naruto's positive attitude might initially annoy Dracula, but over time, Dracula could see Naruto's determination as something to admire. They could team up to fight a common enemy, like a group of rogue ninjas who are after the vampire's powers.
One idea could be a story about a new character who arrives at the hotel during the events of the third movie. This character could have a special power that both helps and causes chaos among the hotel guests. For example, they might be able to communicate with sea monsters in a unique way, leading to some hilarious misunderstandings.
One idea could be a fanfiction about Mavis and Dracula going on an adventure together to discover a new magical place for the hotel. This would focus on their relationship and the expansion of the hotel's world.
In a fanfiction, perhaps some of the Hotel Transylvania characters could have chakra. Mavis, for example, could discover she has a special type of chakra that gives her the ability to control bats in a new way. She could then go on a journey to the Naruto world to learn more about chakra and meet characters like Kakashi who could teach her about different chakra natures.