One possible motive could be jealousy. Maybe Tonks is jealous of Hermione's intelligence or the attention she gets from others in the wizarding world.
She may also use her quick thinking and intelligence. For instance, she could try to reason with Tonks, appealing to their shared values or common friends in the wizarding community. If Tonks is acting out of a misunderstanding, Hermione could talk her out of it by presenting facts and explanations. Hermione is known for her logical thinking, and this could be a powerful defense tool.
One possible motive could be jealousy. Maybe Molly is jealous of Hermione's close relationship with her son Ron. Another could be that she feels Hermione is a bad influence on the family in some way, perhaps her non - pure - blood status makes Molly, who has some traditional views, act out. Or it could be a misunderstanding, like Hermione being wrongly accused of something that makes Molly think she's a threat to the family.
It could be that Tonks represents something Moony doesn't like. Perhaps she's associated with a group or an idea that he opposes. On the other hand, Hermione is known for her loyalty and her ability to think on her feet. Moony might value these qualities and thus like her in the fanfiction.
One possible motive could be love. Maybe she fell in love with someone who was an enemy of House Black and chose that person over the loyalty to the house. For example, if she was in love with a member of the Order of the Phoenix who was against the dark ways of House Black.
In fanfiction, Tonks is often depicted as bold and free - spirited. Her ability to change her appearance adds an element of mystery and fun. Hermione, on the other hand, is usually her studious and rule - abiding self. But in fanfiction, she may be more open to Tonks' wilder side. For example, Tonks might convince Hermione to break a small rule for an adventure. Their relationship is usually one of mutual respect, with Tonks admiring Hermione's intelligence and Hermione being intrigued by Tonks' unique magic.
Well, one possibility could be that in this fanfiction, Lupin sees Hermione's intelligence and loyalty in a way that he feels a deeper connection with her compared to Tonks. Maybe Hermione helps him in some sort of magical research or during a difficult time at Hogwarts, and through those experiences, his feelings for her grow stronger than his feelings for Tonks.
Hermione is also highly respected by the teachers and other authority figures. She's often given important tasks and responsibilities. Tonks, on the other hand, might feel that she doesn't get the same level of recognition. So, in the world of fanfiction, this could be a reason for her jealousy towards Hermione.
One common theme is friendship. Fanfictions often explore how Hermione and Tonks become friends and support each other. Another theme is female empowerment. Since both are strong female characters, they are shown as being independent and capable in many stories.
It could also be that Dumbledore has some secrets that he's afraid Hermione will uncover if she's left to her own devices. Hermione is known for her inquisitive nature. So, to keep these secrets hidden, he attempts to control her. For instance, if there are some hidden aspects of Hogwarts' history or certain faculty members that he doesn't want exposed, he might use control over Hermione to prevent her from delving too deep.
Well, if Hermione was Tonks' sister in fanfiction, it could lead to some really interesting changes. For example, Hermione might be more involved in the Order of the Phoenix from an earlier stage. Since Tonks was part of it, Hermione could have insider knowledge and be more directly involved in the fight against Voldemort. Also, it could change her relationship with Harry and Ron. Maybe she'd be more secretive about some things because of her connection to Tonks and the Order.