Perhaps she'll face some initial doubts. Even though she's brilliant, she could wonder if she really belongs at Hogwarts. This could lead to an interesting internal struggle where she has to overcome her insecurities before fully embracing the opportunity presented by the letter.
She might be overjoyed. In the 'Harry Potter' world, getting the Hogwarts letter is a big deal. Hermione is a book - loving and eager - to - learn character, so when she gets her letter, she could immediately start preparing for her new adventure at Hogwarts, like gathering all the necessary books and supplies.
It's possible that she'll share the news with her Muggle parents in a very careful way. She would need to explain the concept of Hogwarts and magic to them. This could be a challenging yet heartwarming part of the fanfiction as she tries to make her parents understand her new world.
In this fanfiction, perhaps Hermione might be even more excited than in the original story. She could start preparing for Hogwarts immediately, reading every book she can find about the school.
Perhaps she gets hurt while trying to protect someone she cares about. She could be shielding a friend from an attacker's blow, and in the process, take the brunt of the injury herself. This would then set up a story of her recovery and the revenge she might seek on the one who caused the harm.
Well, he could become corrupted. Frostmourne has a history of corrupting those who wield it. Anduin, being a paladin, his struggle between the light and the dark could be a central theme. Maybe he starts to question his beliefs in the light.
Well, in fanfiction when Saitama gets drunk, he may interact with other characters in a different way. For example, he could become more talkative and engage in long conversations with villains or heroes alike. This could lead to some unexpected alliances or rivalries. Also, his physical abilities might be affected in strange ways. Maybe he would still be strong but lack the precision he usually has, resulting in some clumsy but still powerful actions.
In a 'naruto gets captured' fanfiction, he might be tortured for information. His captors could be after the secrets of his Nine - Tails chakra. They may try to use him as a bargaining chip against Konoha.
In a 'l gets kidnapped fanfiction', there could be a lot of drama. Maybe his friends would start a search mission right away. They might follow some small clues like a piece of cloth from his clothes left at the scene.
Well, in the 'sonic gets a makeover fanfiction', Sonic could be given a makeover by his friends. They might change his color scheme a bit, like adding some blue highlights to his fur. His speed could also be enhanced in a new and exciting way as part of the makeover. Maybe he gets some new power - up items that are integrated into his new look.
In some fanfictions, Dumbledore is portrayed as having a lot of secrets. If he gets caught, it could be related to his past. Maybe some old enemies find out where he is and catch him. Then he would have to deal with his past coming back to haunt him. His friends might try to rescue him, but it would be a very difficult situation for him, and it could change the whole dynamic of the fanfiction story.
In the 'tohru gets sick fanfiction', perhaps her friends would be very worried about her. They might take turns to take care of her, bringing her warm soup and making sure she takes her medicine on time.
In the 'ichigo gets drunk' fanfiction, he might act in a very uncharacteristic way. For example, he could start being overly friendly or saying things he normally wouldn't. Maybe he'd lose his usual cool composure and start blabbing about his deepest secrets or feelings towards his friends or enemies.