Perhaps the Veela has some sort of magical bond with Hermione that Snape discovers. He then uses his knowledge of dark magic (not in an evil way) to try and break the bond. In the process, Hermione starts to see Snape in a new light, as a protector rather than just a strict teacher. And the Veela becomes more and more possessive as it feels its connection to Hermione slipping away.
One possible plot could be that the possessive Veela has an interest in Hermione and sees Snape as a rival. Snape, in his usual brooding way, tries to protect Hermione from the Veela's overbearing nature. This could lead to a series of tense encounters where Hermione is caught in the middle, not fully understanding the Veela's motives or Snape's sudden protectiveness.
One common theme is the power struggle. The Veela's possessive nature represents a powerful force, and Snape, with his own power and knowledge, battles against it for Hermione's well - being. Another theme is the exploration of Hermione's character. She is often put in a position where she has to be strong and make difficult decisions between the two very different forces in her life.
One possible plot could be that Hermione breaks a major rule in Snape's potions class, like using an unapproved ingredient. Snape punishes her by making her clean all the potion vials in the classroom after hours. This gives them a chance to have some tense conversations where Hermione stands up for herself and Snape realizes she's not just a rule - breaker but a passionate learner.
One possible plot could be that Snape, in a rather devious way, tempts Hermione with the knowledge of some long - lost, powerful magic. He might dangle the opportunity to study it in front of her, knowing her thirst for knowledge. Another could be that he tempts her with a chance to change some past events in the wizarding world that she has always regretted not being able to influence. For example, he could offer her a way to prevent certain tragedies that occurred during the wizarding wars.
In some fanfictions, Snape might blackmail Hermione over her grades. For example, he could threaten to expose some small mistakes she made in her potions work if she doesn't do him a favor, like helping him organize his ingredients. This creates a tense situation between them and often leads to Hermione trying to outwit Snape in some clever ways.
One possible plot could be that Hermione is stalking Snape to uncover some long - lost potions secrets that she believes he has. Maybe she suspects he's hiding a powerful antidote formula. Another plot could involve her stalking him because she thinks he has a connection to a dark wizard from the past and she's trying to prove it to protect Hogwarts. And in some fanfictions, she might be stalking him out of pure curiosity about his personal life, which is always so mysterious in the original series.
In some fanfiction, the son might have a special ability that combines Snape's Occlumency skills and Hermione's quick - thinking. He could use this ability to solve mysteries at Hogwarts. For instance, there could be a mystery surrounding an old magical artifact, and he uses his combined skills to figure out its purpose and protect it from those who would misuse it.
One interesting plot could be that in a post - war Hogwarts, Hermione discovers a hidden side of Snape through his old potions notes. She becomes intrigued and starts to work on some of his unfinished experiments, which leads to a series of adventures where she gradually understands his complex character better. This could involve her having to face some of the same challenges he did, like dealing with the dark arts influence in certain potions.
Another plot could be a time - travel scenario. Queen is magically transported to the wizarding world and meets a younger Snape and Black Hermione. Queen's different style and music could inspire Black Hermione to create new kinds of magic spells that are more in tune with creativity and self - expression. Snape, on the other hand, is skeptical at first but later realizes the potential of this new form of magic.
Hermione's Veela heritage could make her more alluring and confident. In the presence of Snape, this might initially annoy him as he is used to seeing Hermione as just a studious Gryffindor. However, as time goes on, her Veela charm could start to break down his cold exterior. For example, in some fanfictions, Hermione's Veela side might cause her to be more assertive with Snape, challenging his views in a way that he can't ignore.
Well, in fanfiction, the idea of Snape being possessive of Hermione can stem from the need to create new and exciting story arcs. Snape has his own set of insecurities and Hermione has her strengths. By making Snape possessive, it can explore how these two very different characters interact on a more intense level. It might also be a reaction to the lack of such a relationship in the original series. Fanfic writers take this opportunity to play with emotions, power dynamics, and character growth within this new relationship concept.