A plot twist could also be that Dabi's amnesia is only partial, and he forgets key events related to his quirk. For example, he might not remember how he got his blue flames or how to control them properly. This would make him vulnerable in battles, and he'd have to relearn everything about his power. It could also lead to some unexpected alliances as other characters either try to take advantage of his weakened state or help him regain his strength and memory.
One possible plot twist could be that Dabi forgets his hatred for his family. This would completely change his dynamic with his father, Endeavor. Instead of seeking revenge, he might start to question the reasons behind his former animosity. Maybe he'll even try to reconcile with his family members, which would shock everyone around him, especially those in the League of Villains who were counting on his vendetta to fuel their plans.
Another interesting plot twist could be that Dabi forgets his identity as a villain. He might wake up thinking he's an ordinary citizen. This could lead to him getting involved in heroic acts by accident. As he tries to figure out who he is, he could start to develop a sense of justice that is completely at odds with his former self. And when his past as a villain starts to resurface, he'll have to face the moral dilemma of choosing between his new - found good side and his old villainous ways.
One interesting plot twist could be that Ranma forgets not only his identity but also his martial arts skills. This forces him to start from scratch, and in the process, he discovers new ways of fighting that are different from his traditional training. Another twist might be that he forgets his relationships, but starts to fall in love with Akane all over again in a completely new way, leading to a more complex and fresh dynamic between them.
One possible plot twist could be that the kidnappers are not who they seem. Maybe they are being controlled by an ancient evil force that wants to use Legolas for some dark ritual. Another twist could be that Legolas is kidnapped as a decoy to draw out his friends, and then the real target is revealed later. For example, the kidnappers might be after a powerful elven artifact that Legolas's friends possess.
A great plot twist could be that Jacob discovers he is not actually a werewolf but a hybrid of some sort, created by an ancient magic that the Quileute tribe has long forgotten. This would make his relationship with both the vampires and his own pack very different and full of new tensions.
One interesting plot twist could be that they discover their twin bond gives them shared magical abilities that are unique. For example, they might be able to combine their powers to create a new kind of spell.
One interesting plot twist could be that Itachi has a hidden motive that is actually to protect Sasuke from a greater threat. Maybe there's a powerful enemy that Itachi knows will target Sasuke, so he kidnaps him to keep him in a secret location and train him in secret. Another twist could be that Itachi is being controlled by some dark jutsu and he doesn't really want to kidnap Sasuke but has no choice. This could lead to a journey of Sasuke trying to break the control over Itachi. Also, it could be that Itachi kidnaps Sasuke to reveal some long - hidden family secrets that Sasuke needs to know in order to become stronger.
One possible plot twist could be that while drunk, Kagome accidentally reveals her true feelings for a certain character she has been hiding them from. For example, if she has a secret crush on Inuyasha, in her drunken state, she might blurt out something like 'I've always loved you' which could create a whole new dynamic in their relationship.
One plot idea could be that Hiccup forgets all about his dragon - training skills and his relationship with Toothless. So, he has to start from scratch, relearning how to communicate with Toothless. This would create a lot of humorous and touching moments as Toothless tries to remind Hiccup of their bond.
A possible plot twist could be that a maester discovers a way to use steam power to bring the dead back to life in a more controlled way. This would completely upend the power dynamics in Westeros. The Night King would no longer be the sole controller of the undead, and different factions might try to use this new - found 'life - giving' power for their own gains, whether it's to replenish their armies or to use the undead as a workforce in the new industrial settings.
One interesting plot twist could be that when they go back in time, they accidentally change a small event that has huge ramifications in the future. For example, they might prevent a key Hollow attack that was originally supposed to happen. This would then change the relationships between characters. Maybe Ichigo doesn't meet some of his friends in the same way because that Hollow attack was a catalyst for many things in the original timeline. Another plot twist could be that they find out there's a hidden force that has been manipulating time all along and they have to fight against it to set things right. And a third could be that when they go back, they discover that their own powers work differently in the past, which adds a whole new layer of challenges for them to overcome.
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.