Well, think about Neville. In the Marvel Universe, he could be like a plant - based superhero. His skills with Herbology could translate into the ability to control and communicate with plants, much like Poison Ivy in DC but in a more heroic way. As for Luna, her unique way of seeing the world might give her an edge in detecting hidden threats or understanding alien species. She could be like a psychic or a seer in the Marvel Universe, helping heroes anticipate danger.
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.
He could fit in as a new kind of hero. His magic would be something unique compared to the existing powers in the Marvel world. He might join the Avengers and use his spells during battles. For example, he could stun enemies with a simple 'Stupefy' spell or create a large magical explosion with a more powerful incantation.
Hermione would be a great asset. She could use her vast knowledge to help the Avengers understand magic better. Ron could provide some comic relief and also be a good fighter with his Weasley - made magical items. Neville could show his courage and perhaps teach the Avengers about some magical plants that could be useful in battles.
In fanfiction, Harry Potter's magic might introduce a new cultural element. The wizarding world has its own traditions and values. This could influence the characters in the Marvel Universe. For instance, the concept of house loyalty from Hogwarts might be adopted by some superhero teams. Also, the magic could add new types of challenges. Magic - based threats might emerge that the Marvel heroes are not used to dealing with, like dark wizards or magical creatures.
The magic of Harry Potter in the Marvel Universe, from a fanfiction view, would likely bring a whole new dynamic. Harry's ability to apparate could be a huge advantage in battles or getting out of dangerous situations quickly. However, it might also be difficult for him to control his magic in a universe with so many different types of energy and power sources. His magic might interact in strange ways with things like the Infinity Stones. Maybe the time - turning spell could have unforeseen consequences when used near the Time Stone, causing ripples in the fabric of time that are different from what either universe is used to.
It would be a very difficult fit. Since the wizarding world has its own norms like monogamous relationships in most cases (like the marriages we see in the series). If one were to introduce concubines, it would have to be in an alternate universe where the social and moral values are completely different. Maybe in a fanfic where the wizarding world is modeled after a more ancient and permissive society, but this would be a huge departure from the original feel of the Potterverse.
Mileena could be a foreign exchange student of sorts from a different magical realm. Her unique appearance and combat skills would make her stand out at Hogwarts. She might have trouble adjusting to the more academic and rule - based magic of the wizarding world compared to her own more instinctive and combat - focused magic.
He could fit in as a unique hero. His magic could be seen as a special power like the others in DC. For instance, he could use his Patronus charm to fight off fear - inducing villains.
Alucard could be a part of an ancient prophecy in the Harry Potter fanfiction. His arrival in the wizarding world could be foretold. He might be seen as a savior or a bringer of chaos. His powers could be seen as a necessary evil to defeat a greater threat, like a new and more powerful form of Voldemort. He would bring his own brand of violence and mystery to the relatively more structured world of Harry Potter, making for a very exciting and unpredictable story.
Hawkgirl could be a new kind of magical creature. Her ability to fly with her wings would be a unique form of magic in the wizarding world. She might be a protector of some hidden magical place in Hogwarts or the Forbidden Forest, like a guardian of an ancient magic that Voldemort is after.