What are some interesting ideas for a Harry Potter crossover fanfic?

One idea could be that Hogwarts students discover Pokemon in the Forbidden Forest. They could start training them and use their powers in magical duels. For example, Pikachu's electric attacks could be used against dark wizards. Another idea is that Pokemon could be used in the Triwizard Tournament tasks, adding a new and exciting element to the competition.

A more complex idea would be a plot where Voldemort somehow discovers the immortality of the vampires in the Twilight world. He tries to make an alliance with them to gain more power, but the vampires are hesitant as they don't want to get involved in the wizarding war. This would create a lot of political intrigue and power struggles.

One idea could be that the Winchester brothers from Supernatural end up in the wizarding world of Harry Potter. They could be on a hunt for a supernatural creature that has found a way to hide among the wizards. Another idea is for Harry Potter and his friends to encounter a case of demonic possession in Hogwarts, and they have to team up with the Supernatural crew to solve it.

One idea could be a wizard from the Harry Potter world accidentally traveling to Forks. Maybe they mistake the vampires in Twilight for some kind of dark magic creatures. They could then try to use their magic to either fight or understand them.

One idea could be a spell gone wrong in the wizarding world that somehow transports some Hogwarts students to Forks. They then have to deal with the vampire and werewolf situation there while also trying to find a way back home. Maybe Hermione could be intrigued by the science - like aspects of the Twilight world that seem so different from magic.

One idea could be that the characters from 'The Magicians' end up at Hogwarts for a magical exchange program. They'd have to adapt to the different magical rules and culture there. For example, Quentin might be fascinated by the concept of houses at Hogwarts, while Eliot could get into trouble for trying to introduce some of his more 'adult' magic tricks from Brakebills.

One idea could be that Chuck, with his knowledge of the supernatural, ends up at Hogwarts. Maybe he's there to investigate some strange magical occurrences that are linked to his world's demons or angels. He could form an unlikely friendship with Harry Potter, and together they figure out how to stop a dark force that's using both magic and the powers from Chuck's universe.

One idea could be that Voldemort discovers the Infinity Stones and tries to use their power to conquer both the wizarding world and the Muggle world. The Avengers, with the help of Harry Potter and his friends, must stop him. They could combine magical spells with superhero powers to create unique battle strategies.

One idea could be that Voldemort teams up with a powerful Marvel villain like Thanos. This would force the Avengers and the Harry Potter characters to join forces. The Avengers could bring their strength and high - tech weapons, while the Harry Potter characters use their magic. Another plot could be that a magical artifact from the Harry Potter world is lost in the Marvel universe and both groups have to search for it. Maybe it has the power to destroy both universes if misused.

One idea could be that Voldemort somehow makes an alliance with Loki. The Avengers would then have to team up with Harry, Hermione and Ron to stop them. They could combine magic and superpowers in battles. For example, Iron Man could use his technology to analyze and counter some of the dark magic spells while Harry uses his Patronus to protect the group from Loki's illusions.