In this type of fanfiction, Hermione would likely experience a great deal of internal conflict. On one hand, she has her own moral compass which is firmly against Voldemort's ideology. On the other hand, she's in his care. This could lead to her developing a stronger will and a more nuanced understanding of good and evil. Voldemort could develop a strange sort of affection for Hermione, which would be a new aspect to his character. He might be more protective of her than his other followers. And for the other Hogwarts students, they would view Hermione with a mix of fear and confusion. Some might try to rescue her, while others would be too afraid to get involved.
Perhaps Voldemort adopts Hermione with an ulterior motive at first, like using her intelligence to further his own dark plans. But as he spends time with her, he starts to develop a strange sort of paternal feeling. Hermione, on her part, could try to subtly change Voldemort's views. She might introduce him to the value of Muggle - born magic and the importance of equality, which could gradually make Voldemort question his own pure - blood supremacist ideology.
Harry might become more conflicted. He has to deal with his own moral compass while being in such an unthinkable relationship. Voldemort could potentially start to show a softer side as he is now in a relationship with Harry. Lucius might regain some of his lost honor as he is now part of this unique union.
She could develop a more assertive personality. As a tomboy, she might become more outspoken and not be afraid to voice her opinions, even if they go against the norm. For instance, she could challenge the old - fashioned views of some of the Hogwarts professors regarding gender roles in magic.
One possible plot development could be Malfoy struggling to fit into Hermione's world. He might be resistant to her friends and the values they uphold. Another could be Hermione trying to get Malfoy to accept his new family situation. Maybe there would be a plotline where Malfoy's old pure - blood family tries to interfere with the adoption.
Hermione might also develop a different perspective on power. When bound, she is in a powerless state. This could make her re - evaluate how power is used in the wizarding world, and she could become more empathetic towards those who are oppressed. In addition, she may become more creative in her problem - solving skills, as the usual magical solutions might not be available to her while bound.
For Hermione, she might develop a more empathetic side towards Snape. She could start to understand his past traumas and the reasons behind his cold exterior. This could make her less judgmental and more open - minded. As for Snape, he could soften up. With Hermione's influence, he might show his more vulnerable side and let go of some of his grudges, especially towards the students he disliked at Hogwarts.
Well, in this fanfiction, perhaps Voldemort adopts Harry because he realizes Harry has some unique power that he wants to control. As Harry grows up, he starts to understand Voldemort's motives and tries to find a way to break free. He could also form unexpected alliances with some of Voldemort's followers who have a change of heart.
Hermione herself would also develop. With the support of two former adversaries, she might gain more confidence in dealing with the pure - blood elite. She could learn to trust them and in turn, teach them things about the Muggle - born perspective. This triangular relationship could lead to all three characters growing in unexpected ways.
Hermione might develop a stronger sense of loyalty towards her family's name. As Sirius was from the Black family, she would want to uphold the family honor, which was previously tarnished. So she could be more protective of her family's legacy in the wizarding world.
Well, if Hermione was adopted by Voldemort in fanfiction, it would completely change the dynamic. First, Hermione's intelligence could be used in very different ways. She might be forced to use her knowledge to help Voldemort's dark plans, but she could also secretly try to undermine him from within. Second, her relationships with other characters would be altered. For example, her friendship with Harry and Ron would be put to the test. They would likely see her as a traitor at first, but later might realize she's playing a double - game. And finally, Voldemort himself might change. Having Hermione around could expose him to different ideas, though he'd probably resist them. It's a really interesting concept for a fanfiction.