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.
One popular plot twist could be a character from the original Naruto series having a completely different backstory. For example, Sasuke might be revealed to have a secret connection to an ancient clan other than the Uchiha. Another is when a new character is introduced who has the power to change the entire shinobi world order. And sometimes, Naruto himself might gain a new and unexpected power that is not related to the Nine - Tails, like the ability to control time on a small scale.
A plot twist could also be that Fem Naruto's chakra has an unexpected effect on Doflamingo's powers. Since Naruto's chakra is often depicted as something very special and powerful in the Naruto universe, when combined with Doflamingo's Devil Fruit abilities in the One Piece world, it could create a whole new set of abilities or problems. For instance, her chakra might nullify his power temporarily, leading to a situation where he has to rely on her for protection in a dangerous encounter.
In some fanfictions, a great plot twist could be that the drunken swordsman's drunkenness is a ruse to hide his true form or power. When in a real battle or a crucial moment, he sobers up instantly and reveals his true, extremely powerful self. This transformation catches everyone off - guard and completely changes the dynamics of the fight and the story.
A really cool plot twist could be that the other characters in the Naruto universe have their own hidden connections to the Indra - Ashura cycle. Maybe Sasuke is not the only one with a significant connection to the past. This could lead to a whole new set of alliances and rivalries. For instance, a character like Sakura could be revealed to have a minor connection to one of the predecessors in the cycle, which would add a new layer of complexity to her character and her relationships with Naruto and Sasuke.
One interesting plot twist could be that Hinata loses her memory. Naruto has to work hard to make her fall in love with him all over again. He shows her all the things they used to do together, and slowly, she starts to remember bits and pieces. This adds a whole new layer of drama to their relationship as Naruto is desperate to get back what they had and Hinata is confused yet drawn to him.
One interesting plot twist could be that the fourth hokage didn't actually die when he sealed the nine - tails in Naruto. Instead, he was trapped in a sort of limbo within Naruto's mind and could communicate with him at crucial moments, guiding him in ways that no one else could understand.
One interesting plot twist could be that an unexpected character enters the Chunin Exams. For example, a character from a far - off village who has a secret connection to one of Naruto's harem members. This could lead to new rivalries and alliances within the exam.
One interesting plot twist could be that the pregnancy was a result of some sort of magical or forbidden jutsu gone wrong. Maybe a villain was trying to use Naruto or Itachi for an experiment and it led to the unexpected pregnancy. This would add a layer of mystery and danger to the story.
One interesting plot twist could be the Ten - Tailed God having a different origin than in the original Naruto story. Maybe it was created by an ancient, long - forgotten clan instead of being a natural force. Another could be that the main character, Naruto, has a special connection to the Ten - Tailed God that gives him powers beyond what was thought possible in the original series. For example, he can control the Ten - Tailed God without the need for the traditional chakra control methods.
In 'The Switch of Fates' fanfiction, Naruto and Hinata's roles are sort of switched. Hinata is the one who has to go on a big adventure to save the village while Naruto is the one supporting her from the sidelines at first. It flips the typical narrative and creates a whole new set of interesting situations and character developments.