One common plotline could be a healing scenario. Maybe Harry is injured and Severus uses his fingers to perform some kind of advanced healing spell on him. This could lead to a deeper connection between them as Harry realizes Severus isn't as bad as he thought.
Another plotline might be a situation where Severus fingers Harry as part of a spell - casting duel. In a tense moment during a magical battle, Severus might use a spell that requires him to touch Harry with his fingers to disarm or disable him. This could then lead to a power struggle and character development as they both deal with the aftermath.
There could also be a plotline where Severus fingers Harry in a moment of intense emotion. For example, if Severus discovers a hidden secret about Harry that makes him both angry and protective. His fingers on Harry could be a physical manifestation of his conflicting emotions, and this could set off a chain of events in the fanfiction such as a search for the truth or a change in their relationship.
Common themes include the mending of broken relationships. Given Severus and Remus' history in the original story, their relationship would need to evolve for them to raise Harry together. Another theme is the protection of Harry. Both Severus and Remus have strong protective instincts in the original series, and in these fanfictions, they would combine their efforts to keep Harry safe. Additionally, the theme of Harry's self - discovery in relation to his new family structure is often explored, as he tries to understand how he fits into this unique family unit.
One common theme is the exploration of their changed relationships. Normally at odds, as wolves they have to find new ways to interact. For example, Draco's superiority complex might be challenged when he realizes Harry and Severus have different strengths as wolves.
One common theme could be the struggle with acceptance, both from themselves and from those around them. Another might be the exploration of how their relationship changes with this new development.
One common plotline is that Draco inherits some sort of ancient magic or a powerful artifact that gives him control over Harry. Another is that a dark wizard forces Draco to be Harry's master as part of a devious plan. Maybe to turn Harry to the dark side or use him for some evil purpose. And sometimes, it's just a result of a magical accident that binds them in this master - servant relationship.
Another theme is the exploration of the wizarding world's reaction. In many of these fanfictions, the wizarding community is either shocked or gradually accepting of their relationship. It shows how they deal with the social implications, like dealing with the Daily Prophet's potential gossip or the reactions of their friends and family.
Well, family drama is a very common theme. Harry and Snape would need to build a relationship, which would be full of tension and misunderstandings at first. The theme of legacy also plays a role. Harry would inherit not only from the Potters but also from Snape. And there's often the theme of acceptance, both Harry accepting Snape as his father and the wizarding world accepting this new family situation.
A common plotline is that Lily survives and reveals some long - hidden secrets about the Potter family or the prophecy. For instance, she might know more about the connection between Harry and Voldemort than anyone thought. This knowledge could then be used to better prepare Harry for his future battles.
Often, there are plotlines about him using his vampire abilities to fight against dark forces in the wizarding world. His enhanced strength and speed could give him an edge in battles.
One common plotline is Severus becoming Harry's protector. He may start to train Harry privately to make him stronger. Another could be Severus confronting Harry's abusers, whether it's the Dursleys or others in the wizarding world.
One common plotline is them trying to change the Slytherin house's negative image. They bring their Gryffindor values like bravery and loyalty into Slytherin and try to reform it from within. Another is their relationship with the other Slytherins. They might have to deal with the pure - blood supremacist ideas that some Slytherins hold. Some fanfictions also explore how they adapt to the Slytherin common room and its more secretive atmosphere.