Some characters in Westeros might be very suspicious of Harry. His strange clothes and the way he does magic would make them think he's some sort of dark sorcerer. Others, like the more open - minded ones, might be curious and want to learn from him. For example, Tyrion Lannister might see Harry as an interesting oddity and try to figure out how his magic works.
The settings themselves are a unique aspect. Combining the magical, school - based setting of Hogwarts with the vast, medieval - like kingdoms of Westeros. You might have a scene where a Hogwarts student is exploring the Red Keep in King's Landing, or a Westerosi knight is trying to understand the moving staircases in Hogwarts. It's a really fun mix of two very different fictional worlds.
If Harry Potter were in Westeros, he could bring some of his own unique magic skills. For example, his ability to fight dementors could be useful against some of the dark forces in Westeros. However, he'd also face challenges. The society in Westeros is based on a feudal system, and he'd need to find his place in it. Maybe he'd join one of the houses and use his magic to help them in battles or in solving internal problems.
If Harry Potter ends up in Westeros in a fanfic, he could bring some new ideas about magic. The people of Westeros are used to their own kind of sorcery. Harry, with his knowledge of spells like Expelliarmus and Wingardium Leviosa, might either be seen as a great asset or a threat. He could also make friends with some of the characters. For example, he might bond with Arya Stark over their shared skills in combat and stealth, albeit in different ways. He could also potentially teach some of the younglings in Westeros about his type of magic, which could change the balance of power in the land.
One great 'harry potter westeros fanfic' is 'The Wizard in Westeros'. It combines the magical elements of Harry Potter with the political intrigue of Westeros in a really interesting way. The main character, a young wizard from Hogwarts, finds himself in Westeros and has to navigate the complex power struggles while also hiding his magical abilities.
The fem Harry Potter could also change the power balance. If she aligns herself with a particular house, that house would gain an edge. Her knowledge of magic could be used to uncover secrets in Westeros, like hidden passages in castles or ancient prophecies that were previously unknown. This new information would disrupt the existing plans of the different factions vying for the Iron Throne and other power positions.
He would probably start by trying to understand the magic in Westeros. Since it's different from what he knows, he'd need to be cautious. Maybe he'd find some similarities between the two magics and build on that.
In fanfiction, 'Harry Potter changes Westeros' could be through his magic skills. For example, his spells like Wingardium Leviosa could be used to move heavy objects in Westeros, which might change the way battles are fought or construction is done. His knowledge of the magical world could also introduce new concepts to the people of Westeros.
One possible plot could be that Harry and Hermione somehow end up in Westeros through a magical portal. They might use their magic skills from the wizarding world to deal with the political intrigue in Westeros. For example, they could help a certain house in the Game of Thrones - like scenario, using spells to protect their allies or uncover the secrets of their enemies.