One possible plot could be Naruto struggling to control the power within Danzo's arm. Maybe the arm has some unique jutsu or abilities that Naruto has to learn to master. He might face challenges from those who fear the power of the arm or want it for themselves.
He could develop a sense of responsibility towards the power the arm holds. Since Danzo misused power, Naruto would strive to use it for good. This could lead to him becoming more mature and strategic in his approach to protecting the village. For example, he might study Danzo's old battle strategies stored in the arm's memories and adapt them to his own fighting style, all while maintaining his core belief in friendship and loyalty.
He'll likely lose his power and influence in the village. Once Naruto reveals his secrets, the villagers won't trust him anymore. His actions might be put on trial, and he could be exiled from the village.
It could also be due to Naruto's outcast status in the village initially. Danzo might think that banishing Naruto would be an easy decision as Naruto doesn't have many supporters at first. He might believe that by getting rid of Naruto, he can maintain the status quo in the village and prevent any disruptions that Naruto's presence might cause in the future.
Well, in some versions, Naruto might use his influence among the villagers. After Pain's attack, the village is in a state of rebuilding and re - evaluating. Naruto, being a hero, has the ears of the people. He could start by presenting evidence of Danzo's underhanded deals, like his connection to Orochimaru perhaps. Maybe he found some secret documents during the chaos that Pain caused, which link Danzo to unethical experiments or power - grabbing within the village.
Sasuke could be a candidate. Given their complex relationship, Sasuke might find a way to give Naruto a new arm as a way to atone for their past differences. He could have discovered some rare medical ninjutsu during his travels or come across a powerful artifact that he uses to create a new arm for Naruto.
One possible motive could be to gain control over Naruto's power. Since Naruto has the Nine - Tails within him, Danzo might want to use that power for his own political or military gains. He's always been power - hungry and sees Naruto as a tool to achieve his goals of making Konoha stronger in his own way, which might involve more underhanded and controlling methods.
It could also be a completely new character introduced into the fanfiction. A foreign ninja who was inspired by some of Danzo's ideas (not the bad ones) and comes to Konoha to take on the role of successor, bringing in new perspectives and ways of doing things.
There's a fanfic where Danzo tries to manipulate Naruto for his own political gain. However, Naruto, being the perceptive character he is, quickly catches on. This leads to a battle of wits between them. In the end, Naruto uses his own brand of talk - no - jutsu to make Danzo see the error of his ways and they end up working together to reform the village's political system.
One way Naruto could be like Danzo in fanfiction is through their view on secrecy. Danzo was big on keeping secrets and operating in the shadows. A fanfic could write Naruto into a scenario where he has to keep important information from his friends, believing it's for their protection, much like Danzo did. This would be a huge departure from his normal open and honest self.