Hermione might be portrayed as more vulnerable than in the original series. Being kidnapped by Dark Harry would put her in a position where she doesn't have the upper hand. However, she would still retain her intelligence. So, she could be shown using her brains in a more desperate and sneaky way to outwit Dark Harry.
At first, their relationship would be very strained due to the kidnapping. But as the story goes on, they could start to understand each other's motives. For example, if Harry was forced to kidnap her for a noble reason, Hermione might gradually forgive him. Their relationship could then develop into a deeper friendship with more mutual respect.
In this type of fanfiction, it might be that Harry has been misled by false prophecies. He kidnaps Hermione thinking he is doing the right thing. As the story unfolds, Hermione uses her intelligence to make Harry see the truth. They then team up to face the real threat that was behind the false prophecies all along. It could also involve a lot of emotional turmoil between the two characters as they deal with the situation, with their friendship being put to the test.
In some fanfictions, Bellatrix might kidnap Harry with the intention of turning him to the dark side. She could try to corrupt him by showing him the power and 'glory' of the dark magic she practices. This would be a huge psychological battle for Harry as he has always been firmly against the dark arts.
One common plot could be that Dark Harry has some twisted plan for Ginny. Maybe he wants to use her as bait to draw out the Order of the Phoenix. He might keep her in a hidden, dark location like an abandoned castle or a secret dungeon. Another plot could involve Dark Harry believing Ginny has some special power or knowledge that he needs for his evil deeds.
One great 'dark harry and hermione fanfiction' is 'The Darkened Path'. It explores a darker side of Harry's character and his relationship with Hermione in a world filled with new and dangerous challenges. Another is 'Shadows of the Soul' which delves deep into their characters as they face a much more menacing magical world together.
Dumbledore could play a crucial role in her rescue. He has great wisdom and powerful magic. He might sense that Hermione is in danger through his magical connections. Then he could send some of the more skilled members of the Order of the Phoenix, like Sirius or Lupin, to find and rescue her. They would be able to use their combat skills and magic to overpower Rabastian.
Ginny often reacts with defiance. She's a strong - willed character. So, she might fight back against Dark Harry, both physically and verbally. She could try to escape at every opportunity, using her knowledge of magic to her advantage.
I'm not sure about the most popular ones specifically for this type of fanfiction. But there are often many talented and relatively well - known authors in the broader Harry Potter fanfiction community. Some might write this darker take on Hermione and Harry's relationship.
Yes, it is quite a popular theme. Many fans are intrigued by the idea of a 'dark' Harry and his relationship with Hermione. It offers a different perspective on the characters, exploring their personalities in a more edgy and complex way. Writers can delve into the dark side of Harry, perhaps influenced by the challenges he faced, and show how Hermione might be drawn to or deal with this new aspect of him. It also allows for creative reinterpretations of the magical world they inhabit.