I think Harry Potter himself would be very powerful in this crossover. He has the experience of fighting dark wizards and his magic skills. If he was in the MHA world, he could use his magic to enhance his physical abilities like the characters with quirks. His ability to resist the Imperius Curse and his knowledge of defensive magic would give him an edge over many MHA villains.
Thor could also be very powerful. He has his Asgardian strength and his hammer (or Stormbreaker). If he were to also gain the ability to use magic like the wizards in Harry Potter, he could be near - invincible. He could call lightning while also casting spells. And his knowledge of different realms could give him an edge in any battles that span across the combined universes.
Honestly, it might be a combination of characters. For instance, if Batman and Hermione Granger worked together. Batman is known for his intelligence and strategic planning. Hermione is extremely intelligent and well - versed in magic. Batman could come up with a plan to take on a powerful enemy, and Hermione could use her magic to execute it. They could analyze the enemy's weaknesses, whether it's a superpower or a type of magic, and then use their combined skills to defeat them. This combination of brains and magic could make them a very powerful force in the combined fanfiction world.
However, Harry Potter himself could also be very powerful in this crossover. He has a lot of experience with dark magic and defeating powerful villains. When combined with the unique magic of SVTFOE, he could become even more powerful. For example, he could use his knowledge of the Deathly Hallows and combine it with Star's Butterfly magic to create new and unbeatable defenses or attacks.
Sasuke could also be a very powerful character in this crossover. His Sharingan abilities combined with some of the dark magic from the Harry Potter world could make him a formidable opponent. But then again, Hermione with her quick thinking and ability to master new spells could also hold her own against him. It really depends on how the crossover is set up and what abilities are allowed to be combined.
It could be Akuma. He is extremely powerful in the Street Fighter universe with his dark Hadou powers. In a combined universe, his ability to manipulate dark energy could be enhanced by the magic in the Harry Potter world. He could potentially learn spells and use them in combination with his fighting skills, making him an almost unstoppable force.
It's hard to say. Harry Potter has his powerful magic, like the ability to cast powerful spells and his connection to Voldemort which gives him certain powers. But Jack Sparrow has his wits and his charm. He's able to talk his way out of almost any situation and has a great deal of experience in combat and survival. So, it really depends on the situation. In a straight - up magical battle, Harry might have the upper hand, but in a situation where negotiation or outsmarting the enemy is key, Jack could be the more powerful one.
It's hard to say. Naruto has his huge chakra reserves and powerful jutsu. But Harry has the power of love and some really strong spells. However, I think Dumbledore would be very powerful in this crossover. He has great wisdom and extremely powerful magic. He could probably figure out how to use Naruto's chakra to his advantage if they were on the same side.
In a crossover, it could be argued that Harry Potter is the most powerful. His magic can do things that are beyond Batman's physical capabilities. For example, he can apparate, which is a form of teleportation, and he can use spells to immobilize or defeat his enemies. While Batman is a formidable fighter and detective, he doesn't have the ability to counteract magic directly. However, Batman's strategic mind might be able to find ways to work around Harry's magic, but in terms of raw power, Harry has the edge with his magic.
It's hard to say who would be the most powerful. Harry Potter has his powerful magic, like the Patronus charm and the ability to use the Elder Wand. However, Wonder Woman has her superhuman strength, speed, and combat skills, not to mention her Lasso of Truth. In a way, it depends on the situation. In a magical battle, Harry might have the upper hand, but in a physical combat, Wonder Woman would likely be dominant.
Some might argue that the Scarlet Witch from the Marvel universe (which is related to Captain America's world) could be very powerful in this crossover. Her reality - warping abilities could have a huge impact on the wizarding world. But then again, the wizards have their own ways of protecting their world from such powerful threats, like powerful wards and ancient spells that have been passed down for generations.