There are fanfictions where the wizarding world has turned against Harry, and Snape is at the forefront of the persecution. Harry feels cornered and betrayed, and during a confrontation, he kills Snape out of self - defense and a sense of revenge. Also, some plots involve a corrupted Snape who has joined a new dark wizard group, and Harry is forced to fight and kill him to protect the innocent people in the wizarding community.
In some fanfictions, there could be a power struggle within Hogwarts. Snape tries to take over the school using some underhanded means, and Harry, as the defender of Hogwarts, has to take him down. This could involve a battle where Harry kills Snape. Or, Snape might be possessed by a dark entity, and Harry is the only one with the power to stop it, even if it means killing Snape to free his soul.
One plot could be that Snape is discovered to be working on a new dark magic spell that would endanger the whole wizarding world, and Harry, in an attempt to stop him, ends up killing him. Another could be a case of misinformation. For example, Harry is tricked into believing that Snape killed someone he loves dearly, like Ginny, and in his rage, he kills Snape before finding out the truth.
One common plot is the discovery. Harry might find out through some hidden letters or a magical revelation that Snape is his father. Another plot point could be the reaction of the wizarding community. Some might be shocked, while others might see it as a way to redeem Snape's image.
One possible motive could be that Snape is still deeply influenced by his loyalty to Voldemort in this fanfiction. Maybe Voldemort has some hold over him that forces him to do the unthinkable. Another reason could be a misunderstanding. Snape might believe that Harry has turned to the dark side or is about to, and he decides to take preemptive action to stop what he thinks will be a great evil.
Perhaps in the fanfic, Snape discovers a powerful and dangerous magic that he wants to use for what he believes is the greater good, but Harry sees it as a threat. Harry has always been wary of Snape, and this new discovery could be the tipping point. Also, if Snape were to make a deal with a dark force in order to gain knowledge to defeat Voldemort but Harry misinterprets his intentions, it could lead to Harry killing Snape.
There could also be interesting developments for Harry Potter in such fanfictions. Harry might have a different reaction to Snape. Instead of the complex and often conflicted relationship they had in the original story, Harry could fully embrace Snape as a hero and perhaps learn more about Snape's past and his motives in a more positive light. This could lead to a much closer bond between them, with Harry seeing Snape as a mentor figure in a new way.
One scenario is when Harry is in danger during a duel or a battle. Snape might step in to shield Harry from a dark spell. Another could be when Harry is being bullied by other students or facing unfair treatment from the faculty. Snape, in these fanfictions, uses his position to protect Harry. For example, he might give Harry private lessons to improve his skills and keep him out of harm's way.
One popular theme is the aftermath of Voldemort's death. How does the wizarding world change? Does Harry become a sort of dictator - like figure because of his power? Another theme is the emotional journey of Harry. Killing Voldemort might not be as straightforward as it seems in terms of his mental state. He could be haunted by the act or feel a sense of loss even though Voldemort was evil. Also, the theme of redemption is common. Maybe some of Voldemort's followers are given a chance to redeem themselves in the wake of his death.
The theme of hidden emotions is prevalent. Snape is a very reserved character in the original books. In fanfictions where he admires Harry, his emotions are often hidden beneath his stern exterior. These stories explore how those emotions gradually surface and how Harry responds to this unexpected side of Snape.
You can start by looking on fanfiction websites such as Archive of Our Own (AO3). It has a vast collection of fanfictions from various fandoms, including Harry Potter. Just use the search function and type in 'Harry Snape' to find relevant stories.
Well, some fanfictions might have a plot where Snape and Harry are forced to team up against a new dark threat in the wizarding world. Snape's knowledge of the dark arts and Harry's experience with Voldemort could create a really engaging story. There could also be a plot where Snape discovers a long - lost family connection to Harry, which completely changes their dynamic. In this case, Snape might be more protective of Harry than we would expect, and Harry has to come to terms with this new side of Snape.
One scenario could be when Harry is facing a difficult exam. Snape, despite his usual gruffness, takes Harry aside and tells him to focus on what he's learned rather than stressing about the outcome. This simple yet firm advice calms Harry's pre - exam jitters.