One possible plot twist could be that Naruto, under their training, discovers a new form of chakra that combines the Senju and Uchiha powers in a unique way. This new power might make him a target for other hidden villages who fear his new - found strength.
One possible plot twist could be that Naruto, while being trained by Madara, discovers a hidden agenda. Madara might be using Naruto to gain access to some powerful jutsu or artifact. For example, he could be after the Nine - Tails' power within Naruto in a more devious way than initially thought. Another twist could be that Naruto's new godlike abilities attract the attention of other powerful and malevolent forces from different dimensions, forcing him to fight battles he wasn't prepared for. And perhaps, during the training, Naruto uncovers secrets about the Uchiha clan that Madara has been hiding, which changes his perception of the whole situation.
One possible plot twist could be that Naruto has some hidden Senju abilities due to his relation to Hashirama. This could change the power dynamics in the ninja world. Maybe he could use Mokuton (Wood Style) more effectively than Yamato. Another twist might be in the political arena. His connection to Hashirama could make him a target or a key figure in disputes between different ninja clans. And it could also change his relationship with Sasuke, as Sasuke might view Naruto's newfound heritage in a different light.
One possible plot twist could be that Dante's training methods are so unorthodox that Naruto initially struggles to adapt. For example, Dante might focus on swordsmanship which is completely different from Naruto's usual ninja skills. This could lead to Naruto having to re - evaluate his understanding of combat and power. Another twist could be that Dante has a hidden agenda in training Naruto. Maybe he needs Naruto to face a powerful demon in the Naruto universe that has some connection to the demons in his own world. And finally, Naruto's chakra might interact in unexpected ways with Dante's devil - may - cry powers, creating a new and unique form of power for Naruto that no one could have predicted.
In a fanfiction where Naruto is trained by Hashirama and Madara, he would likely become an extremely powerful ninja very quickly. Hashirama's wood - style jutsu and his ability to control tailed beasts could be passed on, and Madara's combat skills and Sharingan - related techniques might also be taught. Naruto could combine his own Uzumaki chakra reserves with these new skills and become nearly unbeatable.
One possible plot could be that Naruto discovers his true heritage and has to deal with the shock and the new expectations. He might face different reactions from the village, some seeing him as a threat due to his relation to Madara, while others might see him as a symbol of a new era because of his connection to Hashirama.
One possible plot twist could be that Naruto has hidden Uchiha powers. Since he's Madara's grandson in this fanfiction, he might suddenly be able to access the Sharingan or other Uchiha abilities in a unique way. Maybe in a fight, instead of relying on his normal Rasengan, he discovers he can use a powerful Uchiha fire - style jutsu that no one expected.
One possible plot twist could be that the ANBU training reveals a hidden power within Hinata. Maybe during a tough training session, she discovers she can access a new form of the Byakugan that was previously unknown. This new power could change the dynamics between her and Naruto, as he realizes she's even stronger than he thought.
A plot twist could be that Urahara's training makes Naruto lose his ability to use shadow clones for a while. This forces Naruto to rely on other skills he's learned from Urahara, like swordsmanship or some new type of jutsu. It would also make his friends and enemies question his power and how to deal with this new Naruto.
One possible plot twist could be that Zabuza's training methods lead Naruto to develop a darker side. Naruto might start to question his own values as Zabuza's more ruthless ways of fighting seep into his mindset. For example, he could become more willing to use underhanded tactics in battles, which would shock his friends.
One possible plot twist could be that Naruto inherits Hashirama's unique Wood Style jutsu much earlier and in a more powerful form. Since Hashirama was a master of this powerful ability, he might train Naruto intensively in it. This would make Naruto stand out even more in the ninja world and perhaps change the way his peers and enemies view him.