If Hermione was a Death Eater in fanfiction, it would rewrite the narrative in many ways. First, the dynamic at Hogwarts would be very different. Instead of being a top student for good, she'd be feared as a powerful force for evil. Her skills in academics would be used to undermine the school's positive values. Also, the way the story unfolds during the battles would change. She could be the one leading the charge against Harry and his friends, using her strategic mind to try and defeat them. It would be a fascinating exploration of how one character's alignment can change the whole story.
Well, if Hermione was a Death Eater, it would completely turn the original 'Harry Potter' story upside down. For one, her intelligence would be used for the dark side. She might use her knowledge of magic to create new dark spells or help Voldemort in his plans. It would also change her relationships. Her friendship with Harry and Ron would be non - existent or turn into bitter enmity. And Hogwarts would be a much darker place with Hermione on the side of the villains, as she could influence other students to follow the Death Eater ideology.
In such fanfiction, Hermione being a Death Eater could lead to some really interesting character developments. Maybe she has a hidden past or some sort of brainwashing that led her to this side. It would also change her relationships. Ron and Harry would probably be in a state of shock and disbelief, and their quest to defeat Voldemort would become even more complicated as they now have to deal with a powerful Hermione on the wrong side.
In a fanfic where Hermione is a Death Eater, the story would deviate a great deal. Hermione was always the one to come up with plans to fight the bad guys. Now she is the bad guy. Her character arc would be completely reversed. Instead of growing into a powerful and good witch, she would be growing into a more powerful and evil one. This could lead to some really unique plot lines. For example, Harry and Ron might try to redeem her, or they might have to fight her without hesitation. It also changes the power balance in the wizarding world. With Hermione's skills, the Death Eaters could gain an upper hand in many battles and schemes.
It changes the storyline by introducing an unexpected ally. Hermione, who was used to seeing Death Eaters as pure evil, now has to reevaluate her views. This can lead to new alliances and different ways of fighting against Voldemort. For example, she might use the Death Eater's inside knowledge of Voldemort's plans.
On the other hand, she could also become more empathetic. If she is trying to redeem the Death Eater, she has to understand his motives and background. This could lead to a deeper understanding of the people who are drawn to the Dark side, and she may become more forgiving in general. For example, she might start to see that not all Death Eaters are irredeemable monsters.
She might react with caution at first. Given that Death Eaters are known for their cruelty, Hermione would be smart to be on her guard. She would likely start by gathering information about the escaped Death Eater, like his known abilities and any possible weaknesses.
Well, if James is a Death Eater in fanfiction, it completely alters the dynamic at Hogwarts. James would no longer be part of the group fighting against Voldemort. This would mean that many of the events that happened because of the Marauders' resistance to the Death Eaters wouldn't occur. For instance, the creation of the Marauder's Map might not have been for good reasons. And Lily's relationship with James would be much more complex. Maybe she was initially trying to save him from the dark side, but failed.
In some fanfictions, Hermione as a Death Eater is a very interesting and often controversial portrayal. Sometimes, it might show her being forced into the role due to some dark magic or blackmail. This completely flips her good - girl image from the original series and allows for a very different exploration of her character.
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.
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.
In this type of fanfiction, the relationship between Hermione and the Death Eater could be very complex. Maybe it starts as a hostile one, but as the story progresses, they might find some common ground or mutual understanding. It could also be a story of redemption for the Death Eater through Hermione's influence.