One common theme is the clash between Sherlock's rational thinking and the irrationality of the vampire world. For example, he has to use his detective skills to figure out vampire - related crimes while dealing with the fact that vampires break many of the natural laws he believes in.
The mystery - solving aspect remains a strong theme even with the vampire element. Sherlock still uses his brilliant mind to solve crimes, but now he might have additional clues or challenges because of his vampiric abilities. Also, the theme of secrecy is common. Sherlock has to hide his true nature from most people, which adds an extra layer of intrigue to the stories.
A less obvious but still common theme is the exploration of morality. Being a vampire or a werewolf often blurs the lines of right and wrong. Sherlock and John have to navigate through this moral grey area. In some fanfictions, they debate whether it's okay to use their supernatural abilities for personal gain or for the greater good. This exploration adds depth to their characters and the overall story.
A common theme is family. Since they are siblings, a lot of fanfictions explore their family dynamic, how they support or clash with each other. Another is mystery - solving, as both are known for their detective skills. They often team up or compete in solving cases in fanfictions.
A third theme is redemption. Sometimes Sherlock may have made a mistake that led to his being hurt, and the fanfiction will explore how he tries to make up for it or redeem himself. This could be related to a case he mishandled or a relationship he damaged. It gives a deeper look into his character growth and development.
One common theme is isolation. Since Sherlock is often seen as a loner, his depression can intensify this feeling. He may push people away, like John Watson, who are trying to help him. Another theme is self - loathing. Sherlock might feel that his mind, which is usually his greatest asset, is now his enemy. He may struggle with feeling inadequate despite his intelligence.
A common theme is the clash of two different worlds. Sherlock is from a world of pure logic and deduction, while Hermione is from a world of magic. Fanfictions often explore how they interact with each other's worlds. Another theme is the power of intelligence. Both characters are highly intelligent, and stories may focus on how their combined wits can solve problems that neither could alone.
One common theme is Sherlock's unique perspective. His autistic way of thinking gives him an edge in solving cases. For example, he might notice details that others miss because of his hyper - focused attention. Another theme is his struggle with social interactions. Fanfictions often explore how he navigates relationships, like with Watson or Mycroft.
One common theme is the unrequited love. Often, Molly has feelings for Sherlock that he may not initially recognize or reciprocate. Another theme is the friendship aspect. Their relationship starts as colleagues but gradually turns into a deep friendship that could potentially be more. And mystery is also a big theme. Since Sherlock is all about solving mysteries, fanfictions often incorporate this into their relationship, like Molly helping Sherlock solve a mystery related to his past or something.
One common theme is Sherlock's early intelligence. Writers often explore how even as a baby, he can see things that others miss.
One common theme could be the deepening of the relationship between Sherlock and John. It's often explored more intimately in fanfiction.