Maybe there's a plot twist where Hermione discovers that Blaise has a hidden past or a secret mission that he hasn't told her about. This could put a strain on their engagement as she questions whether she really knows him. Or perhaps there's a magical curse that gets in the way of their relationship, and they have to find a way to break it in order to have a successful engagement.
A really interesting plot twist could be that they are engaged as part of a magical experiment. Wizards are testing if a strong relationship between a Gryffindor and a Slytherin can bring about a new era of peace in the wizarding world. Hermione and Blaise initially think it's just about their love, but later find out the bigger picture behind their engagement. This makes them question their relationship and whether they are just pawns in a bigger game.
Perhaps there could be a rival who tries to break them apart. This rival could be someone from Sasuke's past who has a grudge against him and sees Sakura as a way to get revenge. They might spread false rumors about Sasuke to make Sakura question his loyalty.
One possible plot twist could be that an old enemy resurfaces just as they are about to get engaged. This enemy might try to disrupt their relationship by spreading false rumors about Naruto, like he has some hidden dark power that could endanger Hinata. Another twist could be that Hinata's family has some ancient clan secret that surfaces and creates a rift between them and Naruto's side. Maybe the secret is related to a power that the Hyuga clan once had and lost, and they fear Naruto might be involved in its re - emergence in a negative way.
One interesting plot twist could be that just before the engagement, Percy discovers he has some long - lost family secret that might put Annabeth in danger. So he has to decide whether to go through with the engagement or keep her safe first. Another could be that an old enemy resurfaces and tries to stop the engagement by framing Percy for something he didn't do. Annabeth then has to prove his innocence.
A really interesting plot twist could be that Blaise is under a magical curse that affects his relationship with Hermione. The curse could be related to an old feud between their families that was long forgotten. As the story progresses, Hermione might start to notice strange behavior from Blaise and tries to figure out what's wrong. This could lead to a race against time to break the curse before it causes some serious harm, not only to their relationship but also to the wizarding world as a whole. Maybe the curse is slowly spreading and affecting other aspects of the magical realm, and only by Blaise and Hermione working together can they find a solution.
Another plot twist might be that the wizarding world somehow discovers their secret marriage against their will. This could lead to a whole bunch of political and social implications. For example, there could be those who oppose the union due to Hermione's Muggle - born status and Harry being a symbol of the wizarding world. It could spark a movement for or against inter - status marriages in the wizarding community.
Well, a plot twist could be that Mei is actually engaged to Naruto as part of a long - term plan to steal some secret from Konoha. But as she spends time with Naruto, she starts to really fall in love with him. This creates an internal conflict for her as she has to choose between her village's mission and her new - found love. Or perhaps Naruto discovers some dark secret about Mei's past that makes him question their relationship, but then he realizes that people can change and that he still loves her regardless.
The plot could take a turn when the female Naruto's friends and comrades in the ninja world oppose the engagement. They believe that it will disrupt the balance of power or that the prince has some ulterior motives. So, the female Naruto has to choose between her loyalty to her friends and her love for the prince.
One possible plot twist could be that their engagement is part of a political alliance between the ninja world and the supernatural world of Rias. But then they discover a hidden conspiracy within the alliance that threatens both their worlds. So they have to work together to uncover the truth while also dealing with their growing feelings for each other.
One possible plot twist could be that Ichigo struggles to control the Sharingan at first. Since he's not from the Naruto universe originally, the sudden addition of the Sharingan's powers might be overwhelming. He might accidentally activate it during battles in the Bleach world and it could give him an edge in seeing his opponents' moves more clearly, but also make him a target as it's an unknown power in his world.
Another plot twist could be related to the pregnancy itself. What if Sakura's pregnancy was not a natural one but rather the result of some kind of experiment or curse? This could lead to a whole adventure where she has to find a way to break the curse and save her unborn child. She might have to team up with unlikely allies and face powerful enemies in the process.