In this fanfiction, the Harry Potter characters would first be amazed by the physicality of Eyeshield 21. But they would adapt. Neville could use his new - found confidence to be a great blocker on the football field. Luna could see things from a different perspective and suggest unorthodox but effective plays. And Dumbledore, if he were to be involved, could be like a wise coach, guiding the characters through the challenges of this new sport and world.
The wizards and witches from Harry Potter would initially be shocked by the desolate and dangerous world of The Last of Us. However, they would quickly start using their magic. For example, Harry could use his Invisibility Cloak to avoid detection by the infected. Hermione would likely start researching ways to use magic to cure the infection or at least make life easier for the survivors.
Harry would probably use his courage and leadership skills. He'd likely be at the forefront of trying to protect the wizarding world. Hermione would adapt by using her vast knowledge. She might study the Muggle technology behind nuclear war to find ways to counter it with magic. Ron would stick by his friends and use his practical skills. For example, he could help with the logistics of getting supplies to those in need. The three of them together would form a strong unit, just like in the original series, but with a new and much more dangerous threat to face.
Harry would need to learn about the different magical laws in America. For instance, the regulations regarding magical creatures might be stricter or more lenient compared to the UK. He might also have to get used to the different currency used in the American wizarding economy.
He'd probably use his magical training to his advantage. His physical fitness from all the running around Hogwarts and fighting dark forces would help him on the pitch. Also, his ability to stay calm under pressure, like when facing Voldemort, would be useful during important soccer matches.
Well, at first, Felicity might be a bit out of place. However, her skills with technology could give her an edge. She could start by trying to understand the magical energy as a form of power source. Maybe she would try to create some sort of device that could detect different types of magic. In terms of social adaptation, she would probably befriend Hermione quite quickly as they both have a thirst for knowledge. And she would gradually get used to the customs of the wizarding world, like the use of Floo powder and Apparition, though she might try to find a technological explanation for these things at first.
Well, first of all, they would be horrified by the sheer number of undead. But then, they would start using their unique abilities. Neville could use his skills in Herbology to find plants that might be useful in repelling walkers or curing diseases. Luna Lovegood might have some interesting insights into the walkers' existence, seeing them as some sort of magical - like creatures. The wizards would also have to learn how to be more stealthy, as magic can attract unwanted attention. They might start wearing the clothes of the survivors to blend in better and not stand out as targets for the walkers.
Hermione would probably be the first to start studying Pandora's ecosystem. She'd be fascinated by the unique plants and animals. Ron would be a bit more hesitant at first, but he'd quickly warm up when he discovers the delicious new food sources. Harry would be focused on how to use his magic in this new environment and would likely try to make friends with the Na'vi to understand their culture better.
In a frozen wasteland, the Hogwarts students would first need to find a way to protect themselves from the cold. Harry might remember some spells he learned in Defense Against the Dark Arts that could be modified for protection against the elements. Hermione would dig into her books - if she managed to bring any - or use her photographic memory to recall useful information. Ron would be the one to keep an eye out for any immediate threats. As they adapt, they might start to discover new magical properties in the ice and snow. For example, they could find that certain crystals in the ice can be used to enhance their spells, or that the snow can be magically manipulated in ways they hadn't thought of before. This would change their understanding of magic and how they interact with their environment.
He'd adapt well. Harry has always been a leader. As a professor, he'd be able to lead students in their studies. He's patient too. Remember how he helped Neville with his magic? That patience would serve him well when teaching students who might be struggling.
He'd first have to get used to the new technology. If there are new magical devices, he'd need to learn how to use them. For instance, if there are advanced wands with extra functions, it would take him some time to figure them out.