One common theme is friendship. Their bond is often explored in great depth, like how they rely on each other in difficult situations. Another is loyalty. Fanfictions usually show how they are always there for one another no matter what. For example, in some stories, Watson stays by Sherlock's side even when others turn against him.
Another theme is the mystery - solving aspect. Fanfictions usually have them working together to crack cases, with Holmes' brilliant mind and Watson's practical knowledge. In 'The Mystery of the Missing Heirloom' fanfiction, they use their combined skills to find the heirloom. Watson provides medical insights that help Holmes piece together the clues.
One common theme is the deepening of their friendship. Many fanfictions explore how they become closer and more reliant on each other over time. Another theme is mystery - solving together. They are often depicted as an unbeatable team in solving complex cases. And of course, there's the theme of loyalty. Their loyalty to each other is a central aspect in a lot of these fanfictions.
One common theme is the slow - burn relationship. Since they start as friends in the original stories, fanfictions often show their love developing gradually over time. Another theme is the struggle with their own identities. Sherlock being a brilliant but socially awkward detective and Watson being a more down - to - earth and moral man, they have to reconcile their differences in the context of a romantic relationship. Also, the theme of secrecy often appears as they might not be ready to face society's reaction to their relationship.
One common theme is their friendship. It often shows how they support each other through various cases. For example, Watson is always there to pull Sherlock back when he gets too obsessed with a case.
One common theme is the unspoken attraction. In these fanfictions, there's often a lot of tension between Holmes and Watson because they can't immediately act on their feelings. Another theme is loyalty, which is a big part of their relationship in the original stories and is intensified in the yaoi versions.
One common theme is adventure. Since John Watson is often associated with Sherlock Holmes and their detective work, the fanfictions might involve the reader going on adventures with him, solving mysteries. Another theme is romance, of course, as it's 'x reader' so there's usually a romantic element between the reader and John Watson.
One common theme is the battle of wits. Sherlock and Irene are both highly intelligent characters, and fanfictions often focus on their mental sparring. For example, in many stories, they try to outguess each other's plans.
One common theme is the deep friendship that develops into something more. It often shows how their initial acquaintance grows into an unbreakable bond. For example, in many fics, they start as flatmates and gradually realize their feelings for each other.
One common theme is mystery. Since Sherlock is all about solving mysteries, the OC often gets involved in his cases. For example, in many fanfictions, the OC might have some inside knowledge or a unique way of looking at the clues that helps Sherlock solve the mystery faster.
One common theme is family drama. Their relationship as siblings is full of mystery and conflict, which makes for great storytelling. For example, in many fanfictions, they struggle to come to terms with their shared past.