In the wizarding world, there are always threats lurking. Hermione, with her inquisitive nature, sometimes gets into situations where she might be in over her head. Sirius, having a wealth of magical knowledge and experience, is seen as a perfect character to be her protector. Fanfiction writers like to play with this idea, showing how he can use his skills and instincts to keep Hermione out of trouble and safe from harm. It also adds an interesting layer to the relationships within the Harry Potter universe.
In many fanfictions, Sirius Black might protect Hermione from various threats. For example, he could shield her from dark wizards who target her for her intelligence or her connection to Harry. He might also protect her from the more traditional Hogwarts bullies. His protective nature could stem from seeing her as a valuable member of the group around Harry, like a little sister figure.
Imagine a situation in fanfiction where there is a powerful magical artifact that is attracting unwanted attention. Hermione, being one of the few who can understand its significance and power, is in danger. Sirius Black, who has a sense of loyalty to those he cares about, would become her bodyguard of sorts. He would stay by her side, use his magic to create protective barriers, and fend off any who try to harm Hermione or take the artifact from her. He might also teach her some defensive magic techniques that are not taught in the regular Hogwarts curriculum to better equip her for such dangerous situations.
They are often depicted as inseparable in fanfiction because in the original 'Harry Potter' series, they have a very strong relationship. Their friendship grew over the years at Hogwarts, and they had many shared experiences. So, fanfiction writers like to expand on that deep connection and turn it into something even more romantic and unbreakable in their stories.
One example could be a fanfiction where Hermione is in a dangerous situation in the Forbidden Forest. Sirius, being protective, immediately apparates there to save her from a group of dark creatures. He uses his advanced magic skills to fend them off and then takes Hermione back to safety at Hogwarts.
Hermione is also brave. She stands up to her enemies and doesn't shy away from danger. In fanfiction, this trait can be explored further, like in stories where she has to face even greater threats alone, making her a really cool and attractive character.
Often, it begins with Hermione trying to help Sirius deal with his post - Azkaban trauma. She uses her knowledge and compassion to reach out to him. As he heals, he starts to see her in a new light. Their relationship then grows as they start to understand each other better. The lemon parts usually are used to explore their more passionate and private moments, which are often written in a very tender and intense way, adding a new dimension to their relationship.
One popular story might be 'Forbidden Bonds' which explores a unique relationship between them. It delves deep into their characters and how they might interact in a different way than in the original series. The author creates a lot of tension and drama, making it an engaging read.
In a Hermione and Sirius family fanfiction, Hermione might end up marrying into the Black family. Since Sirius was an important part of the Black family before his estrangement, Hermione could find herself involved in the family's complex politics and traditions. She could use her knowledge of magic and her Muggle - born perspective to challenge some of the old - fashioned ideas within the family. Sirius, on the other hand, could be like a mentor to Hermione, teaching her about the more secretive and dangerous aspects of the wizarding world that she might not have known otherwise.
There could be a fascination with power dynamics. Sirius is an older and more experienced wizard in the Harry Potter world compared to Hermione. Fanfic writers may be drawn to the idea of how his knowledge and power could interact with Hermione's intelligence and determination, thus leading to the concept of him dominating in the fanfiction. Also, it might add an element of unexpectedness or novelty to the relationship between two such different characters.
One possibility could be that Sirius sees Hermione's intelligence and determination and decides to take her under his wing. Maybe he realizes her potential and wants to protect her from the dangers in the wizarding world that he has faced himself.