Perhaps the fanfiction could explore how Snape's past actions, such as his spying for Dumbledore and his complex relationship with Harry Potter, are affected by the revelation of his fatherhood. His relationship with the child could also mirror his own troubled relationship with his father, and he might strive to be a better father figure than his own dad was.
Another plot could involve the child having special powers or a unique connection to the magical world because of Snape as their father. For example, they might have an extraordinary talent for potions, like Snape, and this draws the attention of both good and bad wizards. It could create a story full of adventure as the child is caught in the middle of different factions vying for their loyalty.
A great plotline might be that Snape adopts Harry secretly at first. Harry starts to notice some changes in his life, like getting better study materials and more personal attention in his magical education. As time goes on, Snape has to face his own demons while raising Harry. He might struggle with his past hatred for James Potter while seeing James in Harry. At the same time, Harry could be trying to figure out why Snape is being so nice to him all of a sudden, which could lead to a journey of self - discovery for both of them.
In some fanfictions, Snape is indeed portrayed as Harry Potter's father. Fanfiction allows for creative reinterpretations of the original story, and this is one such interesting deviation from the canon where Snape's complex relationship with Harry takes on a whole new dimension.
One interesting plotline could be Snape and Harry having to work together on a secret project for Dumbledore. They start off distrusting each other but as they face challenges, they gradually become friends. For example, they might be researching a powerful dark magic spell that Voldemort is after, and in the process, they learn about each other's past traumas and start to empathize.
Some fanfictions have a plotline where Snape survives the Battle of Hogwarts and he and Harry have to deal with the aftermath together. They might have to face the wizarding community's reaction to Snape's past actions and also work on rebuilding Hogwarts. There are also stories where Harry, while still at school, starts to understand Snape's difficult position between Dumbledore and Voldemort and tries to help him in some way, which creates a whole new dynamic between them.
One interesting plotline could be Harry growing up with Snape's guidance and inheriting his potions skills at an early age. He might have a different dynamic with the other Hogwarts students, being more of an outcast due to his connection to the often - misunderstood Snape.
Well, there could be a plotline where Snape's father was an inventor in the wizarding world. He might have created some powerful magic items or spells that were lost or forgotten. Snape, in the fanfiction, could be on a quest to find and revive his father's work. Another idea is that Snape's father was a key figure in a war long before Voldemort's rise, and his actions had consequences that Snape has to deal with in the present day of the fanfiction. There could also be a plotline where Snape's father was a mentor to some other important character, and this connection has implications for Snape's life and the overall story.
One interesting plotline could be Snape taking on a mentoring role for the Potter twins in a more in - depth way than in the original series. Maybe he teaches them some advanced potions techniques or helps them understand the darker aspects of magic that others might shy away from.
One possible plotline could be Snape revealing the truth to Harry in a moment of crisis. Maybe when Harry is about to face Voldemort alone, Snape steps in and tells him the truth, giving Harry a new motivation to fight.
In some 'Snape Adopts Harry' fanfictions, there is a plotline where Snape and Harry have to work together to uncover a mystery at Hogwarts. This mystery could be related to the Dark Arts or some hidden secrets of the school. Along the way, their relationship evolves from a reluctant guardian - ward relationship to a more loving father - son bond. Harry might start to understand Snape's past actions and Snape, in turn, learns to open up and be more affectionate towards Harry.
One interesting plotline could be Snape realizing that Harry is not like the 'Boy Who Lived' (WBWL) as everyone expected. Maybe Harry has a different approach to magic that Snape initially scoffs at but later comes to respect. For example, Harry might be more interested in the darker arts in a way that challenges Snape's views.