One interesting plot twist could be that Snape, despite his initially cold exterior, uses his advanced potions knowledge to secretly develop a cure for Hermione's head trauma. This would add a layer of complexity to his character as it shows a more benevolent side.
In some fanfictions, Hermione's head trauma might initially make Snape more distant. He may see her as a liability or someone who can't keep up with her studies due to her condition. However, as the story progresses, he might notice her determination to overcome it and start to respect her more.
One plot twist could be that Snape is actually under a spell that makes him fall in love with Hermione. This could lead to a whole mystery about who cast the spell and why. Hermione would then have to figure out whether the love is real or not, while still dealing with the feelings she has developed for Snape. Another could be that they get married in secret, and when it's revealed, it causes an uproar in the wizarding community, with people taking sides either for or against their union.
A really interesting plot twist could be that Snape was under a spell all along that made him seem so cold and distant, and Hermione discovers it. This changes the whole dynamic between them. Another twist could be that Hermione is actually related to someone from Snape's past in a way that they never expected, which brings them closer.
In some fanfictions, a great plot twist is that Snape is not really who he seems in terms of his magical abilities. He might be hiding a much greater power, and Hermione discovers this during a crucial moment. This discovery makes her trust in him even stronger as she realizes he has been hiding his true self not to intimidate others but to protect the wizarding world in his own way. Also, there could be a twist where Snape and Hermione are the only ones who can access a powerful, ancient magic, and this shared ability and the secrets it holds lead to a deeper level of trust between them.
A great plot twist could be that younger Snape actually has some knowledge of Hermione's time - traveling. Maybe he's been having strange dreams about the future and when he meets Hermione, he realizes she's part of it. This would completely change the power dynamic between them.
In some fanfictions, a plot twist might be that the memory was somehow manipulated by a dark wizard. So, what we see as Snape's worst memory was actually a distorted version of the truth. This could lead to a whole new understanding of Snape's character and actions during that time.
Well, a really cool plot twist might be that Snape starts to have his own thoughts influenced by Hermione's. Since he can hear her so often, her way of thinking begins to seep into his mind. Maybe he starts to question some of his long - held beliefs about the Gryffindors or about magic in general. Also, it could be that Hermione discovers a way to communicate back to Snape through her thoughts, like a two - way mental communication, and they start to form a secret alliance that no one else in Hogwarts suspects.
One popular plot twist could be that Snape is actually controlling Hermione to protect her from a greater danger that she's unaware of. Maybe there's a dark wizard targeting her and Snape's control is a way to keep her out of harm's way while he figures out how to defeat the threat.
One possible plot twist could be that Hermione discovers a hidden prophecy that only she can fulfill to save Snape. This prophecy might be related to some ancient magic that Snape has unknowingly become a part of. Another twist could be that in order to save Snape, Hermione has to team up with some of her former enemies, like Draco Malfoy, who also has a vested interest in Snape's survival for some reason. And perhaps the most unexpected twist could be that Snape's salvation is somehow linked to Hermione's ability to time - travel, which she uses to go back and change certain events that led to Snape's peril in the first place.
One possible plot twist could be that Hermione discovers a hidden power within herself that is not in the original books. For example, she might find out she has a special connection to an ancient magic that only warriors possess. This could change her role in the wizarding world completely and lead her on a new adventure to master this power.