A great plot twist could be that Naruto turns out to be a half - vampire. It would completely change his character arc and how others in the Naruto world perceive him.
Perhaps in a Twilight Naruto fanfiction, the Sharingan is actually related to the vampire's ability to hypnotize. So when Sasuke activates his Sharingan, it has an added effect similar to what a vampire can do. This would be a huge plot twist as it links two very different power concepts from the two universes.
Well, one common plot twist could be that the kidnapper is actually a long - lost relative of Bella's with a hidden agenda. Another might be that the kidnapping was a set - up by a jealous vampire from another coven who wants Edward for themselves. And sometimes, it could turn out that Bella has some sort of hidden power that the kidnapper is trying to either use or suppress.
One interesting plot twist could be a new vampire coven arriving in Forks with a different set of rules. They might not believe in the Cullen's way of co - existing with humans. This could lead to a power struggle between the two covens.
One common plot twist could be that the kidnapper is actually a character who was thought to be dead in the original Twilight series. This sudden revelation can completely change the direction of the story.
One interesting plot twist could be that Bella's transformation into a vampire gives her a unique power that no other vampire has. For example, she might be able to control the weather. Another twist could be that instead of joining the Cullen family right away, she runs off on her own to explore the vampire world. Maybe she discovers a whole new coven that has different values and ways of life compared to the Cullens.
One interesting plot twist could be that Bella, as a new vampire, discovers she has unique powers that no other vampires have. For example, she might be able to control the elements in some way.
Well, a plot twist might be that the baby has a special connection to an ancient vampire clan that no one knew about. This could lead to a whole new storyline where they try to claim the baby. Also, Bella could experience a vision during the birth that reveals a future event that changes the course of the 'Twilight' world. Maybe she sees a great war coming and this knowledge makes everyone around her change their plans. It could also be that the baby's birth causes some sort of magical ripple effect that starts to change the abilities of other vampires in the area.
A possible plot twist could be that Naruto's blindness was actually caused by an enemy's secret jutsu that was meant to be permanent, but it turns out that Naruto's Uzumaki bloodline has a hidden ability that can reverse the blindness under certain conditions. This would add an element of mystery and hope to the story.
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.
Imagine a plot twist where the Sharingan and Rinnegan are not unique to the ninja world. In a fanfiction, it could be revealed that an alien race has similar powers. A character from Naruto's world travels to this alien planet and discovers that their understanding of these powers is completely different. They must then adapt to this new knowledge and use it to save both worlds from a common enemy that is drawn to the power of the Sharingan and Rinnegan.
One interesting plot twist could be that Naruto discovers he has a long - lost sibling from a different village. This would completely change his perception of his family and his place in the ninja world.