A possible plotline is the relationship development between Snape and the other Hogwarts staff. They might be skeptical at first about Snape adopting Harry. There could be a lot of tension and drama as Snape tries to prove that he can be a good father figure to Harry, and along the way, he might have to change some of his ways and attitudes towards his colleagues as well.
Another plotline might involve Snape protecting Harry from the dark forces that are still after him. Since Snape has a lot of knowledge about the dark arts and the Death Eaters, he could use this to keep Harry safe in a more effective way than Dumbledore did at times. Maybe he even teaches Harry some special defensive magic that only he knows.
One interesting plotline could be Snape initially struggling with his new role as Harry's guardian. He's used to disliking Harry, but as he gets to know him better, he discovers Harry's hidden talents and insecurities. For example, Harry might show an aptitude for potions that Snape had never expected, and Snape has to learn to be a positive influence in Harry's life instead of a critical one.
A possible plotline is that Snape's adoption of Harry causes a rift in the wizarding community. Some might support it, seeing it as a way to keep Harry safe and under the watchful eye of a powerful wizard. Others might oppose it, fearing that Snape's dark past could influence Harry negatively. This conflict could lead to many adventures and challenges for both Snape and Harry as they try to navigate through the political and social turmoil.
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.
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.
Well, sometimes in these fanfictions, a great plotline is Snape trying to protect Luna from the bullies at Hogwarts. Given Snape's own experiences of being bullied as a child, he would be very determined to make sure Luna doesn't go through the same. He might use his position as a teacher to subtly intimidate the students who pick on her. Also, there could be a plot where Luna starts to teach Snape about the beauty of the natural magic around them. Snape is so focused on the academic and often darker aspects of magic, that Luna's view of the magic in simple things like a butterfly's flight or the way a flower blooms could be eye - opening for him.
One interesting plotline could be Hermione's struggle to adjust to living with Snape. She's used to the warm and inclusive environment of Gryffindor, and Snape's dark and brooding personality makes it a big change for her. Another could be Snape seeing Hermione's potential not just as a student but as a daughter figure, and he starts to teach her advanced magic privately, which in turn helps Hermione to solve some of the school's mysteries.
One possible plotline could be that it's all a misunderstanding. Maybe Snape was under the influence of a dark spell that made him act out of character and hit Harry. Then the story could revolve around Harry trying to find a way to reverse the spell and save Snape from further disgrace.
One interesting plotline could be Snape finally seeing Harry's potential in potions and secretly mentoring him outside of class. This could lead to a grudging respect between them.
One interesting plotline could be how Dumbledore helps Harry discover his true magical potential beyond what he learned at Hogwarts. For example, he might introduce Harry to ancient and rare magic that was long forgotten. Another could be Harry's relationship with the wizarding community changing as he is now seen as Dumbledore's adopted son. This could lead to new friendships and alliances. Also, Dumbledore might train Harry to become a great leader in the wizarding world, preparing him for future threats that are much larger than Voldemort.
One possible plotline could be Hermione using her intelligence to create a stable and loving home environment for Harry. Maybe she helps him deal with his PTSD from his past traumas. Another could be them facing magical threats together as a family, with Hermione teaching Harry new spells and ways to protect himself.
Well, in some of these fanfictions, the plot could involve Harry having to adapt to a completely different world from the wizarding one. Gibbs would be like a father figure, guiding him through the Muggle world's rules and values. There could also be a plot where Harry's past with Voldemort makes him a target in the Muggle world, and Gibbs has to protect him while also trying to understand this whole new concept of magic.