A great plot twist could be the discovery that Naruto and Raven are related in some way through a long - lost multiversal connection. This would completely change their dynamic and the way they interact with each other. Also, perhaps Naruto's ability to transform into different forms gives Raven new insights into her own powers of transformation or shape - shifting. Another plot twist might be that a powerful artifact in the DC New 52 world is actually linked to Naruto's world, and only they can unlock its true potential together, leading to a race against other characters who want to use it for evil purposes.
A really unique plot twist in DC Vampire fanfiction can be that the Green Lantern Corps has to deal with a vampire - like entity that feeds on the energy of their rings. This forces them to find new ways to power their rings and fight this entity. And sometimes, a plot twist is that a vampire version of Aquaman rules the underwater world, and the normal Aquaman has to figure out how to stop him without getting turned into a vampire himself.
One interesting plot twist could be that Naruto discovers he has a long - lost sibling from another village. This would completely change the dynamics of his relationships and his understanding of his own family. Another could be that Sasuke turns out to be the key to a new and powerful jutsu that was sealed away long ago, forcing Naruto to team up with him in a whole new way.
Naruto has the ability to create shadow clones. These clones could be used in combination with Raven's empathic powers. The clones could spread out and gather information about the emotions of enemies in different areas, and Raven could then use this information to strategize better. Also, Naruto's Rasengan, a powerful chakra - based attack, could be infused with Raven's Azarathian magic to create a new, even more destructive attack that has elements of both their powers.
In some fanfictions, a big plot twist is when Naruto suddenly gains a Devil Fruit ability, completely changing the power dynamics. For example, in 'Naruto's Devil Fruit Adventure', he gets a powerful fruit that makes his ninja skills even more formidable.
Perhaps a plot twist where an evil force is manipulating both their universes and they are the only ones who can see the signs. Naruto and Caulifla must put aside their differences and combine their powers in a way no one thought possible to stop this greater evil that threatens both their worlds and the fabric of reality itself.
Well, there's a fanfiction called 'Kyuubi's True Form'. The plot twist here is that the Kyuubi has a completely different true form than what was expected, and this form has different powers and a different relationship with Naruto. Also, in 'Naruto's Lost Kyuubi', Naruto suddenly loses the Kyuubi for an unexpected reason, like a time - travel accident, and he has to find a way to get it back without his usual power source.
One interesting plot twist could be when Naruto's friends turn against him because they fear the power of the lightsaber he wields. It changes the whole dynamic of their relationships.
In some fanfictions, like 'The Secret Alliance', there's a plot twist where Naruto and Kenichi form an unexpected alliance against a common enemy that was thought to be an ally. It completely changes the dynamic of the story.
In some fanfictions, the plot twist could be that the dinosaurs are actually from another dimension sent to the Naruto world to test the ninja. And Naruto is the only one who can communicate with them because of his special chakra. This leads to him having to form an alliance with the dinosaurs to save the world from a greater threat. It's a really unique way of bringing the two concepts together.
Perhaps Madara fakes his death in the fanfiction after meeting Naruto. Naruto then has to deal with the chaos that follows as Madara secretly manipulates events from the shadows. Or, it could be that Naruto's presence causes Madara to have a change of heart, but then the ninja world doesn't believe that Madara has truly changed and they both have to fight against the world's distrust. There are so many ways the plot can take an unexpected turn in this kind of fanfiction.