A possible crossover might involve Aragorn being magically transported to Hogwarts. He could be a bit bewildered at first by all the magic around him, but then he starts to adapt. He might end up training the students in physical combat skills, which are lacking in the wizarding world. Meanwhile, Harry Potter could be fascinated by Aragorn's tales of his adventures in Middle - earth and might even try to incorporate some of Aragorn's courage and honor into his own life.
One possible fanfiction could involve the fem Harry Potter character and an elf (perhaps from the Potterverse like Dobby) meeting Aragorn. They might form an unlikely alliance. The fem Harry could bring her magical skills, the elf its unique abilities, and Aragorn his leadership and combat skills to face a common threat, like a new dark force that spans across different fictional realms.
Well, think about a scenario where the Philosopher's Stone gets stolen and taken to Asgard. Harry, Ron, and Hermione follow it there. Thor, initially suspicious of these strange wizards, eventually realizes they are on the same side. Together, they embark on a quest to retrieve the Stone, with Thor providing his brute strength and the Hogwarts gang using their wits and magic along the way.
One interesting crossover could be Darkseid's quest for the Deathly Hallows. Imagine him believing that these powerful magical artifacts could enhance his already great power. He might send his minions to Hogwarts to search for them, leading to a battle between the students and Darkseid's forces.
Maybe a dark wizard in the Harry Potter universe has found a way to access the power of the One Ring from Middle - earth. Aragorn, sensing the danger, travels to the wizarding world with the help of some elvish magic. He teams up with Harry Potter to stop the dark wizard from using the Ring's power. Along the way, they face many challenges, including dealing with the corrupting influence of the Ring on those in the wizarding world who are power - hungry.
One interesting crossover could be a story where Harry Potter uses his magic to travel to the world of Brandon Stark. Maybe he helps Brandon in his struggles against the White Walkers using spells and potions. For example, he could use a warming charm to protect the Stark soldiers from the cold of the North.
One interesting crossover could be the magical world of Harry Potter colliding with the Titan Shifter's world in a way that the wizards have to face the Titans. Maybe the Titans are immune to some magic spells, creating a huge challenge for the Hogwarts students and professors. For example, Hermione could be researching ways to counter the Titans' abilities using her vast knowledge of magic.
In some fanfictions, there might be a situation where Harry and Anakin are transported to a strange dimension that combines elements of both the Star Wars and Harry Potter universes. They might find themselves in Hogwarts but with the presence of Sith lords and Jedi knights. Here, they would need to use their wits and powers. Harry could use his knowledge of Hogwarts' secrets and Anakin his combat skills and understanding of the Force to navigate this new and dangerous world.
Well, in some fanfiction, we might see Anna and Kristoff visiting Hogwarts. They could be amazed by the moving staircases and magical creatures. In reverse, Harry, Ron and Hermione could end up in Arendelle. Hermione might be intrigued by the way Elsa controls her ice powers and try to find a scientific or magical explanation for it. Also, the Dementors from Harry Potter could be compared to the dark forces in Frozen 2, like the mist that Elsa has to face.
One interesting crossover could be the use of magic in the Avengers world. For example, Hermione could use her knowledge of spells to help the Avengers solve a problem that technology couldn't. Maybe she could use a spell to break through an impenetrable force field created by an enemy. Another aspect could be the Avengers characters learning magic. Tony Stark might be fascinated by the concept of magic and try to incorporate it into his technology. Or Thor could share his knowledge of Asgardian magic with the Hogwarts students.
One interesting crossover could be a scenario where Hermione uses her magic to help Elsa control her powers better. Maybe she creates a spell that can soothe Elsa when she's about to lose control.