Maybe the Time Stone from the Avengers' universe gets mixed up with a powerful time - turning spell in the Harry Potter world. This causes chaos as characters from both universes start jumping through time. Harry Potter and his friends could end up in New York during the Chitauri invasion, and the Avengers could find themselves in the middle of the Battle of Hogwarts. They would have to figure out how to get back to their own times while also helping in the battles at hand.
One idea could be that the Avengers are somehow transported to the wizarding world. They might be initially confused by the magic but then start to work with the Hogwarts students and teachers to fight a common enemy, like a dark wizard who has also harnessed some sort of Muggle - like technology to become even more powerful. For example, Voldemort could team up with Hydra remnants to create a super - weapon that threatens both the magical and non - magical worlds.
Perhaps the wizards from Harry Potter could teach the Avengers some magic. For example, Harry could show them how to use the Patronus charm for protection. In return, the Avengers could introduce the wizards to their high - tech gadgets. Iron Man could be especially interested in the magical properties of things like the Elder Wand. And then there could be a big battle where the combined powers of magic and technology are used to fight off a new, powerful enemy.
Maybe the Time Stone from the Avengers universe gets accidentally sent to the Harry Potter world. This causes chaos as different characters try to use it for their own purposes. Harry and his friends might think it could be used to defeat Voldemort once and for all, while the Avengers are desperate to get it back to prevent time - related disasters in their own universe. Hermione would be very intrigued by the science behind the Time Stone and try to study it, which could lead to some interesting interactions with the science - minded Avengers like Bruce Banner.
It might be because fans love to imagine the magical world of Harry Potter combined with the superhero action of the Avengers. It offers a fresh and exciting take on both franchises.
One idea could be that Tinkerbell finds her way into the wizarding world of Harry Potter. Maybe she gets accidentally transported there by some magical mishap. She could use her fairy magic in Hogwarts, like helping to repair broken objects in a more sparkly and unique way compared to the Reparo charm.
A fun concept could be a Transylvanian wizard coming to Hogwarts as an exchange student. This wizard has a pet dragon that is different from the ones in the UK. He brings with him knowledge of Transylvanian magic, like how to use the power of the full moon in a different way than British wizards do, which intrigues Harry and his friends.
One idea could be that the characters from Riverdale somehow find themselves in the wizarding world of Harry Potter. Maybe Jughead could be a Muggle - born wizard who discovers his powers while at Hogwarts. He might write about his strange new experiences in his journal, just like he does in Riverdale.
One idea could be that Loki, being the mischievous character he is, finds his way into the wizarding world of Harry Potter. He could start causing chaos in Hogwarts, perhaps by disguising himself as a student or a professor and playing pranks that are far more elaborate than those of the Weasley twins. For example, he might turn the entire Great Hall into an ice rink during breakfast time.
One idea could be that the Hulk somehow gets transported to the wizarding world. Maybe a magical experiment gone wrong by a Hogwarts student creates a portal. The Hulk's brute strength would be a shock to the wizards and witches. He could end up causing chaos in Hogwarts, knocking down walls and scaring students. Wizards would try to use spells on him, but his strength might make him resistant at first.
Another possibility is a scenario where Voldemort decides to expand his reach into the non - magical world and Batman becomes aware of this threat. He would then enter Hogwarts undercover to learn about magic and form an alliance with the Order of the Phoenix. The contrast between Batman's brooding, non - magical detective nature and the magical world would make for an interesting story.
One idea could be that Lucifer somehow ends up in the wizarding world. Maybe he's intrigued by the magic there and decides to play some tricks on the Hogwarts students. He could start by disguising himself as a new dark arts teacher, causing chaos in the classrooms.