At the start, Hermione would be appalled by Fenrir's cruelty. She would be enraged that he has caused so much harm to innocent people. But as she delves deeper into getting to know him, she would start to see the complex web of factors that contributed to his behavior. She might see the neglect and discrimination he faced as a werewolf, which could make her feel a bit of pity. However, she would still firmly oppose his cruel actions and try to find a way to either contain or reform him, all while being acutely aware of the danger he poses.
One possible plot could be Hermione's research on werewolves leading her to interact with Fenrir Greyback. Maybe she wants to understand the werewolf curse better and tries to interview him in Azkaban. Through their conversations, she discovers the dark and twisted past that led him to become such a feared and cruel werewolf.
Hermione would likely react with her characteristic intelligence and courage. She would probably try to use her vast knowledge of magic to find a way to escape or at least resist Fenrir. For example, she might try to use spells that could incapacitate him temporarily. She would also be likely to try and outwit him in conversation, looking for any weaknesses or loopholes in his plans.
Perhaps it's the allure of the 'forbidden'. Fenrir Greyback is a dark and dangerous character, and exploring his relationship with Hermione in fanfiction might be an exploration of the contrast between light (Hermione) and dark (Greyback).
In one fanfiction concept, Greyback saves Hermione when she is trapped in a magical maze created by dark wizards. Greyback, being a cunning and experienced dark creature, is able to navigate the maze and get to Hermione before the maze collapses or she is killed by the various traps inside. He might save her because he senses that she has a great potential that could be useful to him in the future.
There's a fanfiction called 'Greyback's Redemption Arc'. In it, Fenrir Greyback saves Hermione from a group of Death Eaters. The author might have written it to explore the idea of redemption for a character like Greyback. Maybe he saves Hermione because he sees her as a symbol of the good in the wizarding world that he has lost touch with, and this act of saving her could be the start of his journey towards redemption.
I'm not sure if there is such a specific fanfiction. It seems like a rather dark and unusual pairing considering Fenrir Greyback is a werewolf known for his brutality. However, the world of fanfiction is vast, and there might be some out there that explore this concept, but it's not a common or mainstream idea in the Harry Potter fanfiction community.
There could be a whole new plotline involving the werewolf packs. Maybe Fenrir Greyback had a specific reason for biting Hermione, and his pack might be involved in some grander scheme. Hermione could be caught in the middle of a werewolf power struggle, having to decide which side to take or how to use her new position within the werewolf community to bring about peace or change.
Harry and Ron would likely be very shocked and concerned. They know Fenrir is a dangerous werewolf, and they might not understand how Hermione got into this situation. They would probably try to persuade Hermione to leave Fenrir at first.
Hermione's character could develop in terms of her understanding of the grey areas between good and evil. Saving Fenrir goes against the common perception of him as a monster. This could make her more open - minded and less judgmental. She might start to see that even the most feared creatures can have a chance at redemption.
Yes, there are likely some fanfictions out there with this theme. However, it's important to note that Fenrir Greyback is a rather dark and dangerous character in the Harry Potter universe, and such a plot might explore some very complex and often disturbing ideas. Fanfiction can take many different directions with this concept, from exploring the horror of Greyback's interest to potential redemptive arcs.