One interesting crossover could be Ben using his alien forms to help the students at Hogwarts during a dark wizard attack. For example, his Heatblast form could be useful against ice spells. Another could be Harry Potter using magic to enhance Ben's Omnitrix. Maybe a spell that makes it transform faster or unlock new alien forms.
Well, in some fanfictions, the characters might interact in really unique ways. Ben could bring some of his tech - like the Plumber's technology - to Hogwarts, which would completely baffle the wizards there. And Harry, with his knowledge of magic, could show Ben things that defy his understanding of science. There could also be a plot where an evil alien is attracted to the powerful magic in Hogwarts and Ben and Harry have to team up to stop it.
In the world of Harry Potter and Ben 10 fanfiction, there are often crossovers that play on the differences between magic and alien powers. Some stories might have Ben's aliens learning magic from Hogwarts professors. For instance, Four Arms could learn how to use a levitation spell to move things more easily. On the other hand, the Hogwarts students could be fascinated by Ben's ability to transform into different aliens and might even try to find a magical explanation for it. Also, there could be a situation where a villain from the Ben 10 universe teams up with a dark wizard from Harry Potter, forcing Ben and Harry to put aside their differences and work together to save both their worlds.
A common crossover concept is the idea of Ben attending Hogwarts. He would bring his street - smart attitude and his alien - fighting skills. His presence could disrupt the normal hierarchy at Hogwarts. He might get into trouble for using his alien powers instead of magic for certain tasks, but also prove to be a great asset when it comes to facing dark wizards. And his friends from the Ben 10 universe could potentially visit Hogwarts too, causing all sorts of chaos and adventure.
In some fanfictions, there might be a plot where the Avengers mistake Ben for a threat at first. But then they realize his good intentions when he helps them fight a common enemy. This adds an element of misunderstanding and then friendship, which is quite common and engaging in crossovers.
In some fanfictions, the technology in Ben 10's world might be combined with Stark's technology in the Avengers. Maybe Ben's Omnitrix could be enhanced by Stark's knowledge, creating a more powerful device that helps them in a battle against an alien invasion. This would involve a lot of scientific discussions and teamwork between Ben and the Avengers, especially Tony Stark.
One interesting crossover could be the Quirk vs Magic aspect. In many bnha harry potter fanfictions, characters from BNHA like Deku might visit Hogwarts and try to understand magic while the Hogwarts students are fascinated by his Quirk. It makes for a great exploration of two very different power systems.
One interesting crossover could be the use of magic systems. In some fanfictions, the characters might combine spells from Harry Potter with the dragon - related magic in Eragon. For example, a wizard from Harry Potter might learn to communicate with dragons like the characters in Eragon.
One interesting crossover could be the use of magic from Harry Potter in the RWBY universe. For example, a character from RWBY might learn how to use spells like Wingardium Leviosa to help in combat or daily tasks. Another could be the Hogwarts houses being applied to RWBY characters, with Ruby perhaps being a Gryffindor due to her bravery.
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.
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.
One interesting crossover could be the use of magic systems. For example, how would the Shadowhunter runes interact with Harry Potter's spells? Maybe a character from the Shadowhunter world could find themselves at Hogwarts and be both amazed and confused by the different forms of magic. Another aspect could be the characters' personalities clashing or working together. A brave Gryffindor and a fearless Shadowhunter might team up to fight a common evil that threatens both their worlds.
One interesting aspect could be the contrast in magic systems. In Harry Potter, magic is more about spells and potions, while Starscream has his own set of technological 'powers' in the Transformers universe. A crossover might explore how they interact. For example, how would Starscream react to a wizard's ability to apparate? And how would a wizard deal with Starscream's flight and weaponry capabilities.