It could be about a student who is being protected by Professor Snape from some dark forces in Hogwarts. Maybe the student has some special power or knowledge that makes them a target, and Snape uses his skills and influence to keep them safe.
In this fanfiction, it might be that the character is a relative of a Death Eater who wants to defect. Professor Snape, being in a difficult position himself, decides to protect this person. He has to balance his double - agent status while ensuring the character's safety. This could involve Snape using his potions knowledge to create protective elixirs, and his skills in the Dark Arts to fend off any threats. There could also be a lot of internal struggle for Snape as he tries to do what's right while still maintaining his cover.
Maybe an orphaned wizard who has a connection to Snape's past. Snape feels a sense of obligation to protect him. This wizard could be the son of an old acquaintance of Snape's, and his presence in Hogwarts stirs up old memories and emotions for Snape. The fanfiction could revolve around how Snape deals with these emotions while protecting the young wizard.
In this fanfiction, there could be a dark force threatening both the wizarding world and the Teletubbies' world. Professor Snape, with his knowledge of dark magic, teams up with the Teletubbies. The Teletubbies have some sort of special power that is related to their connection with nature. Snape has to figure out how to combine his magic with their power to defeat the common enemy. Along the way, Snape's cold exterior starts to thaw as he gets to know the Teletubbies better and they start to respect his skills and wisdom.
One reason could be Snape's knowledge. Hermione, being a knowledge - seeker herself, might feel safe knowing that Snape has a vast understanding of magic, especially the darker aspects. So, she believes he can keep her safe from any threats related to that knowledge.
One idea could be exploring Snape's childhood before Hogwarts. Maybe he had a secret friendship with a Muggle that no one knew about. This could add depth to his character and explain some of his later actions.
One possible plot could be Naruto teaching a new generation of ninjas. He might use his own unorthodox methods that he learned during his own ninja training.
One idea could be that Snape discovers Hermione has a rare magical ability that he's secretly been researching. He takes her on as an apprentice of sorts, much to the surprise of everyone. This could lead to a series of adventures where they explore the depths of this magic together and Snape slowly starts to see Hermione in a new light.
One common plot element could be Snape revealing a hidden, softer side that Harry gradually becomes attracted to. Another might be some sort of magical or emotional bond that forms between them unexpectedly. For example, a shared magical experience that makes Harry see Snape in a new light.
One possibility could be that Harry has faced some extreme danger or a great loss in the wizarding world. Maybe he lost a close friend in a battle, and Snape, despite their past differences, offers him a moment of comfort. Snape, in this scenario, might be showing a side of himself that Harry has never seen before, a more empathetic side.
One possibility could be that the snakes are magically bound to protect Harry. Maybe they are under an ancient spell that makes them his guardians. For example, they could form a protective barrier around him whenever he is in danger, like when Voldemort or his Death Eaters are near.
Perhaps she has inherited Snape's talent for potions and is trying to prove herself in Hogwarts while also dealing with the reputation her father has. She could be bullied because of Snape's cold exterior but then show her classmates her own unique charm and skills.