Draco Malfoy could be a likely character. He was a Death Eater (or on the verge of becoming one), and his relationship with Hermione has always been complex. There's a lot of potential for a story between them as they have a history of rivalry and yet could potentially find common ground or unexpected feelings for each other.
Lucius Malfoy could be another main character. He's an established Death Eater. A story could revolve around Hermione getting involved with Lucius in a political or power - related context within the wizarding world. Maybe she has to outwit him or, in a more unexpected turn, he develops a strange respect for her abilities.
It could be Harry and Ron. In many cases, they might be the ones ignoring Hermione in the fanfiction. Maybe they get caught up in their own adventures or problems and don't pay enough attention to her.
Obviously, some well - known Death Eaters like Bellatrix Lestrange would be likely main characters. Bellatrix is extremely cruel and power - hungry, so she would be eager to get her hands on Hermione. Lucius Malfoy could also be there. He is always looking for ways to gain more influence in the dark wizarding world, and Hermione might be a means to that end for him.
One possible plotline could be a story of redemption. Maybe a Death Eater starts to question their beliefs after getting to know Hermione on a deeper level. For example, they could be forced to work together on a mission and gradually see the good in her, leading to a change in their ways.
Ron could be a main character. He might be the first one to notice Hermione's new haircut. He could have a really strong reaction, like blushing because he suddenly finds her even more attractive with the new look. And their relationship could develop further because of this change in her appearance.
Hermione could resist the Death Eaters with her vast knowledge of magic. For example, she could use protective spells and charms she has learned from her studies. She might also use her quick thinking to outwit them in verbal exchanges, not giving them any information or advantage.
Well, she could end up in a duel with a powerful Death Eater. Hermione is a very skilled witch, so it would be a great show of her magical abilities. Maybe she discovers a new spell during the fight that helps her gain the upper hand.
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.
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.
Luna Lovegood might be involved. She could provide some unique magical items or knowledge to Hermione that helps in the fight against Bellatrix. Also, Severus Snape could be a character in the fanfiction. His complex relationship with both the Order of the Phoenix and the Death Eaters could add an interesting layer to the story. Maybe he has some information that Hermione needs to defeat Bellatrix.
Harry and Ron would most likely be main characters. They are Hermione's closest friends, so they would be involved in her life change. They might be the ones to give her advice or react to her new appearance.