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.
One idea could be that Hermione accidentally travels back in time and meets a younger Severus Snape. She could initially be shocked by his younger appearance and different demeanor. Maybe she tries to help him with his studies or deal with the bullies in his life, which would create an interesting dynamic as she already knows his future self.
Maybe in a time - travel fanfiction. Hermione travels back in time and ends up in Snape's student days. She tries to change some events for the better, and in the process, she gets to know a younger Snape. Their interactions are initially rocky but gradually turn into something more, leading to a kiss. This would be a very different take on their relationship, as it involves a different time period and different versions of themselves.
Well, perhaps the phoenix is actually a guardian of a powerful magic that only Hermione and Severus can unlock together. But there's a catch. They have to overcome their initial distrust and dislike for each other. This would lead to a lot of tense and interesting scenes as they try to figure out how to work together without killing each other first.
One possible plot twist could be that Snape's secret family has a hidden magical ability that is crucial to the wizarding world. Maybe his family has the power to reverse dark magic spells, and this is something Voldemort has been searching for all along.
A possible plot twist could be that Tom Riddle actually becomes a mentor - like figure to Severus Snape in a fanfiction. Riddle, seeing Snape's talent for the Dark Arts, decides to guide him in a different way than the Death Eaters would. This would completely change the way we view their potential relationship.
In some fanfics, a plot twist could be that Severus was actually protecting Hermione all along under Dumbledore's secret orders, and Sirius discovers this and has to re - evaluate his hatred for Severus. This completely changes the dynamic between the three.
Perhaps the baby's existence causes a rift in the wizarding world. Some might view it as an abomination due to the age and past relationship between Hermione and Severus. This could lead to Hermione and Severus having to fight not only for their baby's safety but also for their right to be a family in a world full of prejudice.
The plot could take a really interesting turn when it comes to Voldemort. Since Snape is raising Harry, he might train Harry in a way that Voldemort doesn't expect. Maybe Harry would be more of a spy in the dark side's camp. Snape could also use his position to mislead Voldemort about Harry's true abilities and intentions. This would create a whole new set of challenges and power dynamics in the fight against the Dark Lord. Harry's loyalties would be constantly tested, and his relationship with Snape would be even more crucial to the story.
One unique Severus Snape pregnant fanfiction could be where his pregnancy is part of a time - travel related event. He somehow gets sent back in time while pregnant, and he has to find a way to get back to his own time while also ensuring the safety of the baby. This combines two very different concepts - pregnancy and time - travel - to create a truly original and engaging fanfiction story.
One idea could be a time - travel plot where Hermione goes back in time and has to work with a younger Severus Snape. They could team up to prevent a dark wizard from rising earlier than in the original timeline. This would put them in a situation where they have to trust each other despite their differences in age and temperament.