One common theme is the clash of two different worlds. Harry Potter's magical world and Ms Marvel's superhero world are very different, so exploring how they interact is popular. Another theme is the characters learning from each other. For instance, Ms Marvel could learn about magic from Harry, and Harry could learn about modern technology and heroism from Ms Marvel.
Yes, there are some. You can start by looking on popular fanfic platforms like Archive of Our Own. Just search for 'Harry Potter x Ms Marvel' and you'll likely find a variety of stories, ranging from crossovers where the characters meet in a magical multiverse to ones where they team up to solve a common problem.
One common theme is the clash and subsequent integration of two very different worlds. Harry Potter's magical world and the high - tech, superhero - filled world of Marvel. Another theme is redemption. Bucky Barnes is often on a journey of self - redemption, and Fem Harry Potter, with her own experiences of fighting against dark forces, can play a role in that journey.
If Harry Potter was in the Marvel Universe, he'd probably end up at Xavier's School for Gifted Youngsters. Think about it, a school full of mutants with special powers, and here comes Harry with his wizardry. He'd either be a great asset or cause a bit of a stir. His magical abilities would be a new kind of power that the X - Men and other mutants might not be used to dealing with.
The X-Men are part of the Marvel Comics lineup. They have their own unique place within the Marvel multiverse, with a dedicated fan base and a significant impact on the comic book world.