Well, it could involve Madara having a new purpose. Maybe he decides to help Naruto against a new, greater threat. Since he was revived, he might have a different perspective on the ninja world now.
It would depend on the writer's intention. If the focus is on Naruto's growth, he could start exploring new jutsu or forms of chakra control. Since he was revived by Madara, there might be some dark elements associated with his revival that he has to overcome. Maybe he has to fight off some sort of curse that came with the revival process. And he would have to do this while still trying to protect the people he cares about.
Maybe an old enemy who was thought to be defeated but has somehow returned stronger. Orochimaru could be a possibility. He was always obsessed with power and immortality. If Naruto is revived, Orochimaru might see it as an opportunity to study Naruto's new state of being (since he was revived) and use that knowledge for his own dark purposes.
In some fanfictions, it could be through a strange and powerful jutsu transfer. Maybe Madara, on the verge of defeat, decides to transfer his Rinnegan power to Naruto for some unforeseen reason, like seeing a new path for the ninja world in Naruto.
An unexpected ally could be an old enemy from his past. Maybe a Hollow that he once fought and defeated now sees a greater threat in the situation after Ichigo's revival and decides to team up with him. For example, the Hollow might have information about the new forces that are emerging since Ichigo's return and offers to share that in exchange for some form of protection or mutual benefit.
In fanfiction, if Naruto got the Sharingan from Madara, it would completely change his power dynamic. He would gain the abilities of the Sharingan like enhanced perception, the ability to copy jutsu more easily, and perhaps even access to some of Madara's unique Sharingan - based techniques. This would make him an even more formidable opponent and could potentially change the entire plot of the Naruto universe within the fanfiction world.
In fanfiction, if Naruto gets Madara's eyes, he might gain new and powerful abilities. For example, he could potentially have enhanced visual powers like the Sharingan's precognition in battle. His fighting style would likely change as he adapts to these new eyes. He might also face new challenges as his body adjusts to the foreign power of the Uchiha eyes.
If Naruto gets Madara's power in fanfiction, he would become extremely powerful. His already impressive combat skills would be enhanced to a whole new level. He could use Madara's Sharingan abilities, which would give him an edge in predicting his opponents' moves. Also, Naruto might be able to access Madara's unique jutsu, like the Susanoo. This would make him a nearly unbeatable force in the Naruto universe of the fanfiction, and it could potentially change the entire power dynamic among the characters.
Well, in the world of fanfiction, all kinds of wild ideas can exist. But generally speaking, this is not a common or typical theme. Naruto is a shonen anime with a focus on action, adventure, and the growth of the characters as ninjas. While fanfiction allows for creative reinterpretations, this particular concept strays quite a bit from the mainstream ideas associated with Naruto. It might be a niche concept within the fanfiction community that appeals to those who enjoy exploring extreme or non - traditional storylines.