Well, one plot twist could be that Naruto discovers a hidden ancient power during his banishment. Maybe he finds a long - forgotten jutsu in a desolate place. Another could be that he forms unexpected alliances with former enemies who now see his banishment as unjust. For example, some of the minor villain clans might join him, seeing a chance to overthrow the existing power structure in the shinobi world.
Maybe Naruto gets banished and ends up in a place full of ancient and powerful artifacts. He discovers how to use these artifacts to enhance his own abilities. He also forms alliances with some outcasts in this new place who share their combat skills with him. As a result, he becomes powerful not just in terms of his ninjutsu but also in terms of strategy and teamwork.
A plot twist might be that Naruto discovers that being a monk is actually a key to unlocking a hidden power within him that has nothing to do with chakra. This new power could be related to his spiritual enlightenment and could change the balance of power in the Naruto universe in the fanfiction. Another twist could be that his friends, believing he has abandoned them, turn against him at first, but then later realize that his new path is actually for a greater good and they end up joining him in some way.
It could be the very people who banished Naruto in the first place. They might fear his new - found power and try to stop him from returning to the village or from getting revenge. They would likely use underhanded tactics to try and take him down.
Naruto's character could develop a more jaded side. After being banished, he might start to question the values he once held dear. However, his underlying kindness still remains. He becomes more cautious and calculating with his new power, not wanting to be used again.
One idea could be that Naruto is forced to become a hunter nin after a rogue ninja from another village steals a powerful Konoha jutsu. He has to track the ninja down, using his unique skills like the Shadow Clone Jutsu for surveillance. Along the way, he discovers new chakra abilities that are specific to the hunter nin role.
Perhaps Naruto, as a knight, has to face off against his former ninja comrades who now see him as a threat to the ninja world. They believe his new knightly ways go against the ninja code, creating a conflict between loyalty and his new identity.
Well, one possible plot could be that Naruto is wrongly accused in Konoha and banished. He then travels to the Land of Lightning. There, he shows his amazing skills and strength which are recognized by the people. Gradually, he rises through the ranks and becomes a candidate for Raikage. He uses his ninja way to bring new ideas and unity to the village, facing challenges from traditionalists along the way.
Well, perhaps Naruto is banished due to a false accusation. In his exile, he encounters a group of outcasts who follow the ways of the Onikage. They see Naruto's potential and offer him a place among them. Naruto at first is hesitant but as he gets to know their cause, which might be about protecting the forgotten and oppressed, he decides to embrace the role of the Onikage. He then uses his newfound power and influence to try and change the ninja world from the outside.
In a 'Naruto banished by Sarutobi' fanfic, the plot might revolve around political intrigue within the village. There could be a group that convinces Sarutobi to banish Naruto for their own gains. Naruto, being banished, would likely set out on a journey of self - discovery. He'd meet new allies and foes. He might even discover new powers or lineages that were hidden from him while he was in the village. And all the while, he'd be thinking about getting back to Konoha to clear his name.
If Naruto becomes emperor after being banished, he would likely change the social structure of the land he rules. He has always been an advocate for equality, so he could abolish class systems. His experience with the tailed beasts might also play a role. Maybe he uses his connection with them to gain some sort of divine right to rule. He would also need to deal with political intrigue within his new court, as there would be those who oppose his rule, seeing him as an outsider.