It might also be that Hermione represents something Draco lacks. She is intelligent, confident, and has a strong moral compass. In fanfiction, Draco could be obsessed with her because he secretly admires these qualities and wants to be closer to someone who has them. He might see her as a challenge or someone who can change him for the better.
One common theme is redemption. Draco, who was often seen as a bit of a villain in the original series, is given a chance to redeem himself through his love for Hermione. For example, in many stories, he tries to make up for his past wrongdoings because of his feelings for her.
In some of these fanfics, Hermione is initially oblivious to Draco's obsession. She is so focused on her studies and fighting for the rights of magical creatures that she doesn't notice the dark - haired Slytherin's intense gaze. But as the story progresses, she begins to sense something different about him, which then sets off a chain of events that further explores their relationship.
Another theme is redemption. In many of these fanfictions, Draco's dark obsession is a starting point for his journey towards redemption. He realizes the wrongness of his ways through his feelings for Hermione and tries to become a better person. It's a way to explore the idea of change and growth in a character that was initially portrayed as a bit of a villain in the original series.
One popular 'Draco obsessed with Hermione' fanfiction is 'Isolation' which delves deep into their complex relationship. It shows Draco's inner turmoil as he realizes his feelings for Hermione.
One popular storyline is the 'enemies - to - lovers' trope. Draco starts off hating Hermione as in the original series, but gradually falls in love with her through various encounters. For example, they might be forced to work together on a project for Hogwarts and start to see each other in a new light.
There's also 'Obsession's Price' where Draco's obsession with Hermione takes a turn when they are forced to work together on a secret project. The story is full of tension as Draco struggles with his feelings and Hermione tries to figure out his motives. It's a great read if you like exploring the darker side of their relationship.
One possible fanfic in this vein could be 'Draco's Obsession'. In it, Draco's obsession with Hermione might start from their rivalry at Hogwarts which gradually turns into an all - consuming fixation. This could be due to Hermione's intelligence and her ability to outwit him, making her a constant presence in his mind.
There's also 'Manacled' which has received a lot of attention. In this fanfic, the complex relationship between Draco and Hermione is explored in great detail. The author does an excellent job of building up the tension and the story is full of twists and turns that stem from Draco's obsession. It's a long read but definitely worth it.
Well, it's the contrast between their characters. Draco, from a Slytherin pure - blood family, and Hermione, a Gryffindor and a Muggle - born. His obsession creates a dynamic where you wonder how two such different people could be drawn together. It adds a new layer of complexity to the wizarding world we know from the books.