What are some interesting ideas for 'harry potter and friends crossover fanfiction'?

Imagine if the Dementors from Harry Potter somehow end up in New York where Friends is set. The Friends gang has to deal with the effects of the Dementors, like feeling all their happiness being sucked out. Phoebe, with her positive and somewhat otherworldly nature, could be the one to figure out how to repel them, maybe through her music or some kind of new spell she discovers.

A 'friends crossover fanfiction' with 'How I Met Your Mother' could be really fun. Maybe Ted Mosby could be in New York for a job interview and end up at Central Perk. He meets the friends group and starts sharing his stories about searching for love. The different perspectives on relationships between the two shows would create great storylines.

One idea could be having Harry Potter characters attend an anime - style magic school in Japan. For example, Harry could be a transfer student to a school where they teach magic in a very different way compared to Hogwarts, with elements like anime - inspired uniforms and more focus on martial arts - based magic.

Perhaps there could be a magical object in 'Harry Potter' that is somehow related to the werewolves in 'The Howling'. For example, a spell book that has the secrets to controlling werewolf transformations. The characters from both worlds could be on a quest to find this book and in the process, they learn more about each other's worlds and how magic works differently in each.

Maybe in this fanfiction, the Death Eaters are somehow connected to an evil ninja clan in the Naruto universe. Harry and Naruto then have to team up to fight against this combined threat. Naruto could teach Harry how to use chakra to enhance his physical abilities, and Harry could show Naruto some of the more subtle uses of magic, like invisibility spells that could be useful for stealth missions.

Maybe a Witcher potion - making concept could be introduced to the Hogwarts potions class. For example, a character from Harry Potter, like Hermione, could be intrigued by the complex and powerful Witcher potions. She might try to study them and combine them with her own magical knowledge. This could lead to new discoveries in both magical systems.

Another idea is to have the Death Eaters somehow get access to Hollow powers. This would create a whole new level of threat in the Harry Potter universe. The characters from Bleach could then be called in to help the Order of the Phoenix deal with this new threat. Harry Potter might learn some skills from Ichigo about combat and vice versa.

Another interesting concept is a character from Harry Potter, like Harry himself, ending up in Forks. He could discover the existence of vampires and werewolves there. He might try to use his magic secretly while also being fascinated by the different supernatural rules in that world. He could even form an unlikely friendship with Bella or Edward, sharing his knowledge of magic with them.

One idea could be a crossover with the Lord of the Rings universe. Harry and his friends could find themselves in Middle - earth, having to deal with Sauron's forces while also using their magic. Another could be a crossover with the Star Wars galaxy, where wizards and witches interact with Jedi and Sith. Maybe they could learn from each other's use of the Force and magic.

One idea could be that the Hogwarts students are transported to the world of RWBY. They could learn about Dust and how it's different from magic. For example, Harry could befriend Ruby and they could exchange knowledge about their respective powers. Harry might teach Ruby some basic spells while Ruby shows Harry how to use Crescent Rose.