There are fanfictions that play with the 'swap - roles' trope. For example, Snape is in Sirius's place in the Order and Sirius is in Snape's place at Hogwarts. This allows for a fresh perspective on their characters and how they would handle different situations. It also gives writers a chance to explore their personalities in new contexts.
One popular trope is the 'enemies - to - reluctant - allies'. Given their history of animosity, it's interesting to see them pushed into a situation where they have to cooperate. Another is the 'redemption arc' for Snape, and Sirius being a part of that in some way, either by initially opposing it and then coming around, or being a catalyst for Snape's change.
The 'secret friendship' trope also exists. In some fanfictions, they have a hidden friendship that no one else knows about. This could be due to their shared love for someone (like Lily), or because they secretly respect each other's skills. There's also the 'time - travel' trope where they go back in time and have the chance to change their relationship from the start.
A common trope is the 'Injury Reminder'. In these fanfictions, Snape's limp serves as a constant reminder of a past battle or dark encounter. It adds a sense of mystery and danger to his character.
One popular trope is the redemption arc for Snape in relation to Harry's family. This often involves Snape making amends for his past actions towards James and finally fully accepting Harry as part of Lily's legacy. Another trope is the 'what - if' scenario, like what if Snape had been more involved in Harry's upbringing. There are also fanfictions that focus on Snape protecting Harry's family from hidden threats, using his skills as a double - agent.
A common plot is that Snape uses his position as a double agent to his advantage. He gets close to Voldemort and then at a key moment, he uses a hidden weapon or spell to injure him. For example, he might have a wand with special properties that he uses against Voldemort. This is popular because it plays on Snape's duplicitous nature.
In fanfiction, Sirius Black and Severus Snape often have complex relationships. Sometimes they are portrayed as rivals, with their past grudges from Hogwarts days still lingering. Their different loyalties, Sirius to James and the Order, and Snape to Dumbledore (while being a former Death Eater), add layers of tension.
There are fanfictions where they are forced to team up in a situation outside of Hogwarts. This could be in a post - Voldemort world where they have to deal with the remnants of the Death Eaters. In these stories, they slowly start to understand each other's motives and personalities, leading to a new - found respect and sometimes more than that. It's really interesting to see how different authors play with their characters.
I really like 'A Different Perspective'. In this fanfic, it's set post - war. Sirius, who survived the Battle of Hogwarts, and Severus, who has been pardoned, find themselves living in the same wizarding community. The story focuses on how they both have to deal with their past traumas and how they start to interact with each other. They start off avoiding each other but are gradually drawn together by their shared experiences and the realization that they are not so different after all.
I really like 'A Different Kind of Rivalry'. It shows a unique take on the relationship between Snape and Sirius. Instead of just focusing on their enmity from the original series, it creates a scenario where they have to work together and gradually start to understand and care for each other. It's a refreshing read.
They are an interesting pairing because they are such opposites. Snape is brooding and often seen as the outcast, while Sirius is more bold and carefree. In fanfiction, it's fascinating to see how these two very different personalities could come together.
One common theme is redemption. Given their rocky pasts full of enmity, many fanfictions explore how they can redeem themselves in each other's eyes. For example, Sirius might realize that Severus wasn't all bad, and Severus might come to terms with the fact that Sirius had his own reasons for his actions. Another theme is friendship against all odds. They are two very different characters, but fanfictions often show how they can form a bond despite their differences. This can be really inspiring as it shows that even the most unlikely pairs can find common ground.
The exploration of their shared past is also a big theme. Since they were at Hogwarts together, fanfictions often go back to their school days to show how their relationship could have been different. And there's the theme of the power of love and friendship in unexpected places. Despite their initial hatred, they find a connection that goes beyond what they thought possible. It shows that love and friendship can bloom even in the most unlikely situations.