One interesting crossover could be the use of alien technology to enhance the magical objects in the Harry Potter world. For example, an alien device might be used to make a broomstick fly even faster or a wand with more powerful spells. Another could be an alien species arriving at Hogwarts and the students having to figure out how to interact with their technology while still using magic.
Well, in a Harry Potter and alien tech fanfiction, perhaps the Ministry of Magic could be using alien tech to keep an eye on the wizarding world in a more advanced way. Maybe they have some sort of alien - inspired surveillance system that can detect dark magic from afar. And the Death Eaters might try to get their hands on this alien tech to use it for their evil purposes. Also, an alien race could be interested in the magic of the Harry Potter universe and try to learn it, leading to all sorts of cultural exchanges and conflicts.
There could also be a scenario where Harry Potter has to face the Joker in a psychological battle. Since Harry has faced his own share of dark forces, the Joker's mind - games could be a new and different kind of challenge for him. Harry would have to use his courage and the skills he learned at Hogwarts to outwit the Joker.
One interesting crossover could be the use of magic in the Warframe universe. For example, a Harry Potter character might bring spells like 'Accio' to retrieve items in the middle of a Warframe mission. Or perhaps a Warframe with magical abilities inspired by Hogwarts magic.
One interesting crossover could be a Creepypasta character infiltrating Hogwarts. For example, Jeff the Killer could be lurking in the Forbidden Forest, adding a terrifying element to the otherwise magical place. It would be a really spooky scenario as students unknowingly get closer to this dangerous figure during their adventures in the forest.
One interesting crossover could be a scenario where Alucard uses his vampiric powers to assist Harry in a battle against Voldemort. Maybe Alucard's super strength and ability to transform could give Harry an edge in a difficult fight.
Well, a cool crossover might involve the Grimm from RWBY being affected by the magic in Harry Potter. Maybe the Death Eaters could team up with some of the more evil forces in RWBY. Also, the different houses in Hogwarts could be compared to the teams in RWBY. For instance, Gryffindor's courage could be related to Team RWBY's fearless nature.
A great crossover idea in the fanfiction could be a Quidditch match between Hogwarts and Alfea. The flying skills of the Winx fairies would add a new dimension to the game. And the strategic play of the Hogwarts students would also be interesting to see in combination. Also, the different brooms and flying devices could be compared and contrasted.
A possible crossover could involve the dark forces in both universes. Voldemort and the forces of evil in Harry Potter could team up with some of the villains from Asgard. This would create a huge conflict where the heroes from both worlds, like Harry Potter and the Avengers - like heroes of Asgard, would have to combine their powers to defeat the combined evil.
In Harry Potter and Clannad fanfiction, a great crossover idea is the exchange of character traits. Maybe some of the Clannad characters could be sorted into Hogwarts houses based on their personalities. And vice versa, the Hogwarts students could learn about the strong family and friendship bonds in Clannad. It could also involve a plot where a powerful Clannad character has to deal with the dark magic threats in the Harry Potter universe. This would create a whole new set of challenges and adventures for both sets of characters.
In some Harry Potter and Riverdale fanfiction, the houses in Hogwarts could be compared to the social groups in Riverdale. For example, Gryffindor's bravery could be related to how the Bulldogs in Riverdale stand up for what they believe in. Slytherin's cunning might be similar to how some of the more devious characters in Riverdale operate. And then there could be a plot where characters from Riverdale are sorted into Hogwarts houses and have to adapt to the new environment based on the traits of their houses.
One interesting crossover could be the Avengers visiting Hogwarts. Imagine Iron Man being fascinated by all the magic there and trying to figure out how to incorporate it into his tech. Another could be Harry Potter and his friends joining the Avengers on a mission. They could use their magic in unique ways to help the Avengers defeat a powerful enemy.