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.
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.
Wonder Woman and Ron Weasley could be an interesting combination. Ron is often underestimated but has a lot of heart and loyalty. Wonder Woman, with her strength and noble character, could inspire Ron to be more confident in himself. Ron could introduce Wonder Woman to the fun and sometimes chaotic side of the wizarding world. They could work together to fight off enemies, with Ron using his magical skills and Wonder Woman using her combat and leadership skills.
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.
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.
Definitely Harry Potter and Batman. Harry has his own set of skills dealing with magic and the dark arts, while Batman is a master strategist and detective. They could learn a lot from each other. Batman could teach Harry about non - magical combat and investigation techniques, and Harry could introduce Batman to the world of magic.
Well, if we consider Harry Potter himself, he has the power of love and the ability to face great evil. But when compared to some of the Servants in 'Fate Stay Night', he might seem less powerful at first glance. But his determination and the fact that he has overcome death multiple times could give him an advantage. On the other hand, a character like Archer from 'Fate Stay Night' has a wide range of skills and the ability to analyze situations quickly. In a combined fanfiction, it would depend a lot on the situation and how the powers interact. For example, if it's a battle of wits, Dumbledore or Archer might have the upper hand, but if it's a battle of pure power, Gilgamesh or a magically enhanced Harry Potter could be the victor.
It could be Albus Dumbledore. He has great magical knowledge and power in the 'Harry Potter' universe. When combined with the 'Fate Stay Night' elements, he might be able to outwit even the most powerful Servants. His ability to plan and his understanding of magic could give him an edge in any conflict.
It's hard to say for sure. Superman has incredible strength, speed, and heat vision. But Thor has his godly powers and the mighty Mjolnir. Maybe in a crossover, it would depend on the situation. If it's a fight in space, Superman might have an edge, but if it involves magic, Thor could be more powerful.
It's hard to say for sure, but Superman could be a top contender. His super strength, speed, and flight, along with his heat vision and other abilities, make him extremely powerful. He can withstand a lot of damage and dish it out just as well.