One possible plotline could be Snape teaching Harry advanced potions in secret. This would not only improve Harry's skills but also create a bond between them as Snape shares his deep knowledge of the subject. Another plotline might involve Snape protecting Harry from the more malicious students at Hogwarts, using his reputation to intimidate those who would bully Harry. And perhaps Snape could gradually reveal his true motives and the complex relationship he had with Harry's parents to Harry, leading to a better understanding between them.
A great plotline could be that Snape takes Harry on as an apprentice of sorts in the Dark Arts Defense. Since Snape was a very accomplished wizard in that area, he could train Harry in spells and techniques not taught in the regular curriculum. This could also lead to some interesting interactions as Harry has to trust Snape, who he previously distrusted. Also, Snape might use this opportunity to show Harry how to better control his emotions, which is crucial in magic, especially when facing dark forces.
Perhaps Snape takes Hermione under his wing because he realizes she is being bullied by some Slytherin students for being a Muggle - born. He secretly protects her and in the process, they start to understand each other better. Snape could share his own experiences of being an outcast in Hogwarts when he was a student. This bond could then grow into a sort of friendship where Hermione learns to see past Snape's harsh exterior and Snape starts to respect Hermione's intelligence and tenacity even more.
A plotline might involve Angeal introducing Zack to different aspects of Shinra's inner workings. Since Angeal has more experience, he could guide Zack on how to navigate the politics and power dynamics within the company. Maybe Zack gets into trouble because of his naivete, and Angeal has to bail him out and teach him a lesson about being more cautious. Additionally, the story could show Zack following Angeal on various humanitarian missions, which would help Zack develop his own sense of compassion and duty.
Harry's character often develops a sense of trust. At first, he is likely to be very wary of Snape. But as Snape takes him under his wing, Harry starts to see Snape's good side. This makes him more open - minded and less quick to judge. He may also become more confident in his magic abilities as Snape imparts his knowledge. For example, if Snape teaches him advanced potions, Harry will feel more competent in that area.
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.
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 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.
Perhaps a plot where Severus discovers his demigod heritage and has to balance it with his life at Hogwarts. He could struggle with how to use his new - found powers without drawing too much attention, while also dealing with his complex relationships with other characters like Harry Potter.
One interesting plotline could be exploring Snape's early interactions with the Marauders. Maybe it shows how his enmity with them truly began. For example, it could focus on a particular incident in their school days that was a turning point.