Often, the resemblance could be in terms of the way Naruto stands or moves in these fanfictions. For example, Naruto might adopt a more menacing stance similar to Madara's. Also, his hair could be described in a way that it seems to mimic Madara's wild look, perhaps when he's in the middle of using a powerful jutsu.
In many fanfictions, Naruto's power aura might be written to be like Madara's. The author could describe how Naruto's chakra feels just as overwhelming as Madara's was. His determination and the way he faces his opponents could also be compared to Madara, with a sort of unwavering resolve and a strategic mind.
In this kind of fanfic, the author may describe Naruto's resemblance to Madara in terms of their auras. Naruto could have an aura that is as intimidating as Madara's. For example, when he enters a room, people might feel the same kind of pressure as they would when Madara was around. And perhaps Naruto starts to have some facial expressions that are similar to Madara's, like a certain smirk or a serious frown.
In this fanfiction, Naruto's character development could be seen as a counterpoint to Madara's. Naruto is all about hope, friendship, and protecting the village. Madara has been through a lot of pain and betrayal which led him to a path of destruction. If Naruto is like Madara in this fanfiction, his development might involve a struggle between his own beliefs and the allure of Madara - like power and ruthlessness. However, Naruto would probably still find a way to use any new - found power in a more benevolent way compared to Madara.
Well, in such a fanfiction, it might start with Naruto being in a situation where he becomes Madara's pet. Maybe at first, Naruto is defiant but as time passes, he could start to understand Madara's motives in some strange way. Madara, on the other hand, might initially see Naruto as just a possession but gradually develop a sense of attachment. It could be a really strange and complex relationship that unfolds as the story progresses.
In this Naruto fanfiction, the new character, let's call him Kaito, who looks like Madara, enters the Hidden Leaf Village. He has the same piercing eyes and a similar hairstyle. The villagers are initially on guard, but as they get to know him, they realize he's different. He has his own dreams of bringing peace, not through domination like Madara once aimed for. Kaito begins to train with the young ninjas, sharing his unique combat skills and insights, and gradually becomes an important figure in the village.
Well, in such a fanfiction, Madara's training might enhance Naruto's physical strength. He could teach Naruto some advanced Uchiha techniques which Naruto can combine with his own Uzumaki powers. For example, Naruto might learn better chakra control from Madara, enabling him to use his Rasengan more effectively and with less chakra waste.
There could be a shift from enmity to a begrudging respect. Madara has always been a powerful and feared foe, but with Naruto being stronger, Madara may have to accept Naruto's superiority. Naruto, on the other hand, would likely try to understand Madara's motives better and might try to reform him rather than just defeat him.
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.
Some fanfictions might depict Naruto as having a deeper understanding of the chakra system than ever before. He could have found a way to disrupt Madara's connection to the chakra source, or maybe he was able to use his own chakra in a way that nullified Madara's powerful jutsus. Also, Naruto's experience from all his previous battles might have led him to anticipate Madara's moves and strategies, allowing him to stay one step ahead and ultimately defeat him.
One possible plot development could be that Naruto's new look causes confusion among his friends. They might start to question if he's still the same Naruto they know. Another is that enemies could be either more afraid or more eager to fight him, thinking he has some of Madara's power.
Yes, in many fanfictions Naruto can be depicted as a prodigy like Madara. Fanfiction writers often take the original traits of Naruto, such as his strong will and determination, and amplify them to a level similar to Madara's natural talent. They might show Naruto quickly mastering powerful jutsu or having strategic insights that are on par with Madara, making him a prodigy in that fictional context.