A really unexpected plot twist could be that Kushina has some secret power that she's been hiding, and it's the only thing that can save Itachi from a certain death. But in order to use this power, she has to sacrifice something very dear to her. This would create a tense and emotional situation where both characters have to make difficult choices.
One idea could be a story where Itachi and Kushina meet in a parallel universe. In this universe, the events of the original Naruto storyline are altered, and they end up on the same side, fighting against a new common enemy. Their unique abilities, Itachi's Sharingan and Kushina's powerful chakra, would make for an interesting combination in battles.
Another plot twist might be that Kushina Uzumaki has a secret power that she's been hiding, and Naruto Uchiha is the only one who can help her fully unlock it. However, unlocking this power comes with a great cost that they both have to face together.
One possible plot twist could be that Naruto, after learning more about Itachi's sacrifices for the village, starts to idolize him in a way that changes his own ninja path. He might adopt some of Itachi's stealthy and strategic techniques. For example, he could focus more on gathering intelligence before acting, rather than his usual head - on approach.
Perhaps in this fanfiction, Naruto being born an Uchiha means he has a natural rivalry with Sasuke from the start. Since they both have Uchiha blood, they might compete not just for power but also for the right to be the true heir of the Uchiha legacy. Also, his Uchiha lineage could attract the attention of Orochimaru, who might see Naruto as a new vessel with the potential of the Uchiha powers.
A great plot twist could be that the one who turned Naruto into a vampire lord was actually a long - lost relative who had an ulterior motive. For example, they wanted Naruto to help them take over the ninja world using his popularity and new vampiric powers.
A really interesting plot twist could be that Naruto is not the only 'daughter' of Artemis in the Naruto world. There could be other characters who also have a connection to Artemis, and they initially see Naruto as a threat. This could lead to a lot of internal conflict within the group related to Artemis. Also, what if Artemis has some sort of dark secret or past event that affects Naruto's role in the story? For example, Artemis might have made a deal with an evil force in the past that now comes back to haunt Naruto. And perhaps Naruto discovers that her connection to Artemis is not as straightforward as she thought, and there are hidden motives behind her being brought into the world as Artemis' daughter.
One potential plot twist could be that the marriage is a political move to end a long - standing feud between the two houses. However, there are secret alliances within each house that oppose the union, leading to internal power struggles. For example, some Lannisters might be against sharing power with the Starks, and vice versa.
A plot twist might be that Harry's past enemies from the wizarding world somehow find a way to cross over into the Naruto world. This would force Shikaku and Harry to team up not only with the ninjas but also with some of Harry's old friends from Hogwarts. It would create a really chaotic and interesting situation where two different worlds' powers and skills collide.
A possible plot twist in this fanfiction might be that Naruto's new status as the jinchuriki of Saiken attracts a new group of enemies who are specifically after the power of the Six - Tails. Also, there could be a situation where Naruto's friends start to fear him because of Saiken's power, thinking he might lose control. And perhaps there is a hidden prophecy that only Naruto as the jinchuriki of Saiken can fulfill, which leads to a whole new adventure and set of challenges for him.
One potential twist could be that Percy is actually undercover for the good guys all along while pretending to join Gaea.