One idea could be that Harry would use his magic skills to help the Fellowship in different ways. For example, he could use his Patronus to ward off the Nazgûl, as his Patronus is a powerful form of positive magic. Another possibility is that he would have an interesting interaction with Gandalf, two powerful wizards from different magical worlds coming together.
Well, he could use his magic to help the Avengers in battles. Maybe he could use a spell to disarm Thanos of the Infinity Stones. His broomstick flying skills would also be useful for quick getaways or aerial attacks.
One idea could be a crossover where the characters from Harry Potter are transported to Middle - earth. For example, Harry could meet Aragorn and they could exchange knowledge about magic and leadership. Harry's magic could be a new and strange power in Middle - earth, and Aragorn's warrior skills and wisdom could inspire Harry.
In a fanfiction scenario, Harry Potter in the Game of Thrones world might be seen as a threat by the maesters. They might try to either study him or get rid of him. Harry, on the other hand, could form alliances with some of the outcasts like the Wildlings. He could teach them some basic magic for self - defense, which would change the dynamic of their relationship with the rest of Westeros.
One idea could be a crossover where the characters from 'Harry Potter' end up in Middle - earth from 'Lord of the Rings'. For example, Harry Potter could meet Frodo and they could exchange their experiences of facing great evil. Another idea might be a fanfiction where the magic systems of both worlds are combined, like using a Hogwarts spell to defeat a Mordor beast. Or perhaps a story where Aragorn visits Hogwarts and learns about the different forms of magic there.
Well, Harry Potter would be a very different character in the Game of Thrones world. He'd probably have to deal with the complex politics there. Maybe he'd use his magic to outwit the scheming lords and ladies. He might also form alliances with some of the more honorable characters like Jon Snow. Magic could be seen as a powerful but also very dangerous tool in Westeros, so he'd have to be careful not to draw too much attention to himself.
In a Harry Potter fanfic with the Infinity Stones, the Stones could interact with the existing magical artifacts in interesting ways. The Elder Wand, for example, might have some sort of connection or reaction with the Infinity Stones. Wizards and witches who were already powerful, like Dumbledore, would have to figure out how to deal with these new and extremely powerful elements in their world. It could also lead to new forms of magic being discovered as the Stones' powers merge with the magic already present in the Harry Potter universe.
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.
Well, the wizards would surely have some unique ways to deal with zombies. For example, they could use spells like 'Incendio' to set the zombies on fire. And the protective charms around Hogwarts might keep the zombies out at first. The students would probably be trained to fight them in Defense Against the Dark Arts classes.
His presence could speed up the journey of the Fellowship. Harry's magic could be used to quickly cross difficult terrains or overcome obstacles that the original Fellowship had to struggle with. For example, he could use a spell to create a bridge over a chasm instead of having to find a way around it.
Blake could be a bit of an enigma in Middle - earth. She might have some similarities to the Rangers, as she is used to being on her own and is very stealthy. Her faunus heritage could also add an interesting dynamic, as she could have some unique abilities that are different from the normal races in Middle - earth. Yang, with her strength and courage, would be a great addition to any battle. She could be like a female version of Gimli, always ready for a fight and not afraid to take on powerful enemies.