One possible plot twist could be that Naruto's friends think he's been possessed or something. They would try to find a way to bring the old Naruto back. Another could be that Naruto's new attitude actually makes him a more powerful ninja, which causes some jealousy among his peers.
A plot twist could be that Naruto's change in behavior makes him an outcast in the village. People start to fear him because of his cold and emotionless nature. But in reality, he's on a secret mission to infiltrate a group of powerful enemies. His Ulquiorra - like act is part of his cover. As he spends more time with the enemies, he starts to understand their motives better and realizes that there are shades of gray in the whole conflict, which could lead to him trying to find a more peaceful solution rather than just fighting them head - on like he would have done before.
Maybe Naruto starts to side with the villains because of his new Ulquiorra - like mindset. He might see the world in a more black - and - white way like Ulquiorra did, and think that the villains have a point. This would put him at odds with his former friends and allies. Or perhaps, there could be a situation where Naruto's new coldness is actually a ruse to deceive an enemy that is after him, and he reveals his true self at a crucial moment.
Well, it could mean that Naruto might adopt Ulquiorra's cold and detached demeanor. He might start speaking in a more monotone way, like Ulquiorra. Also, his fighting style could become more calculated and less impulsive, similar to how Ulquiorra approaches battles in a very methodical manner.
A really interesting plot twist could be that Naruto's Dante - like behavior is actually a result of a genjutsu cast by a hidden enemy. As he acts more and more like Dante, his friends start to suspect something is wrong and have to figure out how to break the genjutsu without harming Naruto.
One possible plot could be that Naruto, for some reason, decides to adopt Sasori's more calculating and detached approach to combat. He might start using puppets or puppet - like techniques in battles, much like Sasori did. Maybe he's on a mission where he has to infiltrate an enemy base and he thinks acting like Sasori would be the best way to succeed.
One possible plot development could be Naruto getting into more intense battles with stronger opponents. Since Kenpachi is always seeking strong battles, Naruto may start to do the same. This could lead to him exploring new areas to find worthy foes.
One possible plotline could be Naruto getting some of Kaneki's ghoul - like powers. So he has to deal with the hunger for human flesh in a way that's similar to Kaneki's struggle, but in the Naruto universe. Maybe he tries to resist it while still protecting his village.
Maybe there's a plot where Naruto is influenced by an external force that makes him act like the Joker. He then starts to target the powerful figures in the ninja world, not to defeat them in a traditional sense, but to expose their weaknesses and make them look foolish, just like the Joker does with Batman. And as he does this, his relationships with everyone around him start to crumble.
A possible plot twist could be that Naruto discovers he has a hidden connection to Smaug. Maybe he is related to Smaug in some long - lost magical way. Another twist could be that Smaug is not really a villain in this fanfiction. Instead, he is being controlled by a greater evil, and Naruto has to figure out how to free Smaug from this control. It would change the whole dynamic of their relationship from one of enmity to a more complex situation where they could potentially become allies.
A possible plot twist could be that Naruto turns out to be a keyblade wielder in disguise. This would completely change the dynamic as everyone in the Naruto world and Kairi would be shocked. It could also mean that Naruto has a whole different origin and mission related to the world of Kingdom Hearts.
A possible plot twist could be that one of the Autobots is actually being controlled by an old enemy from Naruto's world. This enemy has found a way to hack into the Autobot's system and use it for their own revenge. So, while the Autobots seem to be helping Naruto, in reality, they might be leading him into a trap.
One possible plotline could be Naruto starting to manipulate the political situation in the ninja world. Just as Aizen had his own designs on the Soul Society, Naruto could use his influence to create power imbalances among the ninja villages for his own gain. Another could be Naruto using his new - found Aizen - like charm to deceive his friends into following a path that they don't fully understand. He might make them believe that he is still the same Naruto, but his actions would be leading them astray.