One idea could be that the Death Eaters initially target Hermione for her intelligence, thinking she could be useful to their cause. But Hermione outsmarts them at every turn, using her magic and wits to escape their clutches and expose their plans to the Order of Phoenix.
Perhaps a plot where a Death Eater has a change of heart after getting to know Hermione. He starts to protect her from the other Death Eaters, and together they try to find a way to end the war in a more peaceful manner, while also facing the challenges of being on opposite sides originally.
One possible plot idea could be Hermione using her intelligence to outwit the Death Eaters in a mind - game. For example, she might pretend to be on their side while secretly working against them to save her friends. Another could be a scenario where she has a strange connection or shared past with a particular Death Eater that she discovers during a dangerous encounter.
One idea could be that Daphne, who may be on the verge of being lured into the Death Eaters' ideology, is saved by Harry. Harry discovers that Daphne has some family pressure to side with the Death Eaters. He tries to show her the true nature of Voldemort and his followers. They form an unlikely alliance and work together to expose some of the Death Eaters' secrets within Hogwarts.
One possible storyline could be a complex exploration of redemption. Maybe a Death Eater has a change of heart after getting close to Hermione, and they both try to work against the dark side from within the Death Eater ranks. It could be full of intrigue as they keep their new alliance a secret.
Maybe Harry has to go undercover among the Death Eaters to gather information for the Order of the Phoenix. During this time, he befriends a Death Eater who is having second thoughts about Voldemort's ideology. They start to work together secretly to undermine Voldemort's plans from within the Death Eater ranks.
In this fanfiction, Hermione could rehabilitate Death Eaters by showing them the error of their ways. She may expose them to the harm they've caused to both the Muggle - born and the wizarding community at large. By making them face the consequences of their actions on a personal level, like the families they've torn apart, she might start to change their views.
A fanfiction involving Hermione and Death Eaters could focus on a moral dilemma. For example, if Hermione has the chance to save a Death Eater's life, would she do it? This could explore her character's sense of right and wrong. It could also be about how she endures the psychological torture that the Death Eaters might inflict on her, showing her strength and resilience.
Well, in some fanfictions, Hermione might use her superior intellect. She could outwit the Death Eaters by setting up elaborate magical traps. For example, she could use transfiguration magic to create objects that suddenly turn into something dangerous when the Death Eaters approach. Another way could be through her extensive knowledge of potions. She might create a potion that incapacitates or kills them when they come into contact with it.
Maybe Hermione discovers that one of the Death Eaters training her has a change of heart. This Death Eater then starts to help Hermione escape or undermine the other Death Eaters from within the group. It adds an interesting layer of complexity to the story.
Well, in this kind of fanfiction, perhaps Hermione is captured because she was on a solo mission to retrieve some important magical item. The Death Eaters could use her knowledge to try and break into the secrets of the Order of Phoenix. Meanwhile, Hermione could be using her wits to delay them and send out hidden signals for help.
One plot idea could be a werewolf Death Eater who is forced to work with Hermione under some strange circumstances. Maybe they are both on a mission to retrieve a powerful magical artifact, and along the way, the werewolf starts to question his loyalty to the Death Eaters as Hermione shows him the value of kindness and justice.