Well, it depends on the specific fanfiction. There are countless fanfictions out there with all kinds of wild ideas. Some authors might create a scenario where Hermione is a spy for the dark just to add an unexpected twist to the story. But in the traditional sense, it goes against what we know of her as a smart, brave and good - hearted character.
One possible motive could be blackmail. Maybe the dark forces have something on her or her loved ones that forces her to spy for them. Another could be a thirst for knowledge. In the 'Harry Potter' series, Hermione is always eager for knowledge. If she thought the dark side had some unique knowledge or power she couldn't get elsewhere, she might be tempted to side with them, at least as a spy.
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.
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.
I'm not entirely sure. In the original series, Hermione is very much against the Dark Arts. However, fanfiction can take characters in all sorts of new directions. It could be that in some fanfictions, the exploration of the Dark Arts is more nuanced and Hermione might be intrigued by that. But it's really up to the individual interpretations within different fanfictions.
In 'Dark Hermione and Dark Bellatrix fanfiction', a common theme is the transformation of character. Hermione, who is typically seen as a good and studious witch, undergoes a significant change to become darker. Bellatrix, on the other hand, may also have her own form of transformation as she interacts with this new, different Hermione. Another important theme is the exploration of the wizarding world's underbelly. These fanfictions often take readers into the parts of the wizarding world that are not so well - known, filled with dark magic and dangerous secrets. It's an exciting way to see the familiar world of Harry Potter from a completely different perspective.
She would probably be very conflicted. Hermione is Harry's friend, and spying on him goes against her loyalty. So she might be constantly struggling with her conscience.
In some fanfictions, Hermione might be a Death Eater spy due to a complex backstory. Maybe she was blackmailed. For example, if the Death Eaters threatened to harm her Muggle - born parents, she could be forced to spy for them. This would be a huge deviation from her canon character, but in the realm of fanfiction, it allows for exploring different character arcs and moral dilemmas.
The main characters are obviously Ron, Hermione, and Harry. Ron is often portrayed as the more impulsive one of the two spies, while Hermione is the more methodical and detail - oriented. Harry, on the other hand, is the one being spied on, who is usually oblivious to their actions at first.
One great 'dark powerful Hermione fanfiction' is 'Hermione Granger and the Time - Turner Conspiracy'. In this story, Hermione discovers a dark secret related to the Time - Turner and uses her newfound knowledge and power in a rather unorthodox way. It really showcases her as a powerful force with a bit of a dark edge.