If Hermione were a spy for the Dark Lord in fanfiction, the plot would change drastically. First, Hermione's knowledge of magic and her intelligence, which were previously used to help Harry, would now be used against him. This could lead to the discovery and capture of many Order of the Phoenix members much earlier. Second, the search for Horcruxes would be in jeopardy as Hermione could lead the Dark Lord's forces to them first. It would also mean that the relationship between the characters would be full of mistrust, especially from Harry and Ron towards Hermione.
Well, if Hermione was a spy for the Dark Lord, it would completely turn the story upside down. For one, the trio's dynamic would be shattered. Harry and Ron would be in great danger as Hermione could pass on all their plans to Voldemort. Hogwarts would no longer be a safe haven as she could leak information about its defenses. And the final battle might not even happen in the way it did in the original, because with Hermione on the Dark Lord's side, he would have a much greater advantage in terms of intelligence and strategy.
Well, if Hermione were the Dark Lord's daughter in fanfiction, it would completely turn the original story upside down. For one thing, her relationships with Harry and Ron would be extremely strained. They are sworn enemies of the Dark Lord, and suddenly finding out that Hermione has such a connection would make them question her loyalty. Also, her place at Hogwarts might be in jeopardy as the school would likely be very wary of having the Dark Lord's kin among them.
Maybe she could be motivated by power. The Dark Lord might have promised her a high position in his new world order. She might also be disillusioned with the wizarding world's current state and think that the Dark Lord could bring about a better change, even if it means using dark magic.
If Hermione was born in the Marauders era in fanfiction, it would be really interesting. Maybe she could use her knowledge of magic, which is quite advanced even for her own time, to help the Marauders in their pranks and also in more serious matters. She might be able to influence the way they deal with Snape, for example. And who knows, she could even be the one to discover some of the secrets that the Marauders had, like how to become Animagi, and use that knowledge to their advantage.
If Hermione was Sirius Black's daughter in fanfiction, it would completely transform her character arc. She would have a different family history to grapple with. The stigma of being a Black might be added to the one of being a muggle - born in the eyes of some. But it could also give her more power and influence within the wizarding world. And Sirius would have a stronger reason to fight against Voldemort, not just for his friends but for his daughter.
If Hermione was Sirius' sister, it would add a whole new layer to the story. Hermione would have access to Sirius' knowledge and resources much earlier. Their combined intelligence and power could have changed the course of the battle against the Death Eaters. Also, it might have affected Hermione's relationships with the other characters. She could be more involved in the Order of the Phoenix activities right from the start.
The power dynamics would shift. Hermione bringing back the dead would likely make her a more controversial figure. The Ministry of Magic might view her actions as dangerous and against the natural order. This could lead to her being hunted or having to go into hiding, which would be a major change from the original plot where she was mainly focused on her studies and helping Harry.
Well, if Hermione was Remus's twin sister in fanfiction, it could change a lot. For one, Hermione's intelligence could be tied to her werewolf heritage in some new and interesting ways. Maybe she'd use her knowledge to find a better way to deal with Remus's lycanthropy. Also, her relationship with Harry and Ron might be different as she'd have this whole other family connection to consider.
She loses her moral compass. Normally, Hermione is a very ethical character, but in these fanfictions, she may start to see the dark arts as a viable option without hesitation. This could lead to her making choices that harm others, like casting harmful spells on those who oppose her.
If Hermione was Dumbledore's granddaughter in fanfiction, it would likely make her an even more important figure at Hogwarts. The teachers might treat her differently, perhaps with more respect or higher expectations. And she could have a different role in the Order of the Phoenix too, being related to Dumbledore. She might be given more dangerous or important tasks.
Well, it could change a lot. For example, Harry might have a different relationship with Hermione. Instead of just being friends, there could be a more complex family - like bond. Maybe Hermione would have some of Lily's traits that could influence how she approaches magic and her relationships in Hogwarts.