What could make a Death Eater be impressed by Hermione in fanfiction?

Bellatrix Lestrange is also a likely candidate. Her encounter with Hermione would be extremely intense. Given her loyalty to Voldemort and her rather unhinged nature, she would likely pose a serious threat to Hermione, but Hermione might also find a way to use Bellatrix's madness against her.

Bellatrix Lestrange's younger brother or some other minor Death Eater character could be used. This would allow for the creation of a new character with his own motives and backstory. He could be betrothed to Hermione as part of a larger plot by Voldemort to gain control over Hermione's knowledge and magic. This would put Hermione in a very difficult position as she would be tied to a very dark and dangerous family.

There's also a possibility that it could be a minor Death Eater that we don't know much about from the original series. The author of the fanfiction could create a new character who was a Death Eater but is now having doubts. Hermione could be the one to find this person and start their journey of change. This would give the author a lot of creative freedom to develop the character's backstory and their relationship with Hermione.

It could lead to an unexpected alliance. If a Death Eater is impressed by Hermione, they might decide to work with her side for a while, which would completely change the power dynamics in the story.

It could also be that Hermione is on a mission to gather information. By helping the Death Eater, she hopes to gain insider knowledge about the Death Eater's group or their plans. This would be a strategic move on her part, using the situation to her advantage in the fight against the dark forces.

One possible motive could be a deep - seated dissatisfaction with the wizarding world's status quo. Maybe she felt that the Ministry of Magic was corrupt and that the Death Eaters had a better vision for change, although a very dark one. Another could be some sort of personal vendetta against someone in the Order of the Phoenix or Hogwarts faculty that made her side with the Death Eaters.

It could be someone who has a hidden good side, like Draco Malfoy. He was from a Death Eater family but showed signs of not fully embracing the dark side. Maybe in this fanfiction, he decides to protect Hermione for some unforeseen reason, perhaps because he has developed a new understanding of the value of life and friendship.

Well, it could be due to a sense of hopelessness. If she feels like the good side is losing the battle against the Death Eaters and there's no other way to protect her friends and the wizarding world, she might think that joining them could give her some power to influence things from the inside. But of course, this would be a very dark path for her to take.

It could be about Hermione facing challenges from a Death Eater while dealing with the slur of being called 'mudblood'. Maybe the Death Eater tries to capture her for some dark purpose, and Hermione has to use her intelligence and magic skills to outwit the enemy.

In such a fanfiction, Hermione might initially be in great danger. The Death Eater could try to capture her to use as leverage against Harry Potter. Maybe she uses her quick wits and vast magical knowledge to outsmart the Death Eater at first encounter.