There are definitely fanfictions that follow this concept. Fanfiction writers often take the basic elements of the Naruto universe and twist them in interesting ways. The idea of Naruto eating chakra to become super powerful fits into this creative exploration. In some of these stories, Naruto might eat chakra that has been stored for centuries, and as a result, he not only becomes stronger but also gains knowledge or wisdom associated with that chakra, which he can then use to his advantage in battles and in making decisions for the greater good of the ninja world.
Well, it depends on the type of chakra. If it's some sort of special or purified chakra in the fanfiction, Naruto could potentially unlock new abilities. Maybe he could gain the power to manipulate elements in a different way or have enhanced speed and strength. It could also have negative effects though, like if the chakra is corrupted, it might put Naruto in a state of internal struggle as he tries to control it.
He might gain an enormous boost in his chakra reserves. This could make his jutsus much more powerful and enable him to perform complex techniques with ease.
Naruto's character would likely become more confident. With the power from the chakra fruit, he'd have fewer doubts about his ability to protect his loved ones and the village. He might also become a bit more reserved as he realizes the magnitude of his new power and the responsibility that comes with it.
In the 'Naruto Becomes Super with IQ 500' fanfiction, Naruto's newfound intelligence could lead to him making amazing scientific breakthroughs in the ninja world. He could understand the chakra system on a whole new level and develop new jutsus that are far more powerful and efficient. His IQ would also help him in diplomatic situations, allowing him to negotiate better treaties and alliances for the Hidden Leaf Village. This would change the power dynamics not only in his village but across the entire ninja world.
In a fanfic where Naruto eats the chakra fruit, he might gain an extraordinary boost in power. His chakra reserves could become limitless, allowing him to perform powerful jutsus without exhaustion. He could also potentially gain new abilities related to the nature of the chakra fruit, like enhanced speed or the ability to manipulate chakra in unique ways.
In Naruto fanfiction, one of the most powerful chakra weapons could be a chakra - enhanced sword that can cut through any jutsu. It's often depicted as being able to disrupt the flow of an opponent's chakra upon contact.
In many fanfictions, Naruto's powerful chakra is often shown as being even more extreme than in the original series. For example, some fanfictions might have him able to use his chakra to create entirely new jutsu that are far beyond what was seen in the anime or manga. His chakra could also be depicted as having unique properties, like being able to heal others just by being in close proximity due to its sheer strength and purity.
In the original Naruto story, Naruto's growth is a gradual process. But in this fanfiction, the chakra fruit speeds things up. This could mean that the story focuses more on Naruto's exploration of his new powers rather than his initial struggles. It might also mean that the story takes a different direction in terms of the villains. New villains could emerge who are interested in Naruto's new power source. Or existing villains might try different tactics to deal with a much more powerful Naruto. Additionally, the role of other characters might change. They could either become more reliant on Naruto or feel the need to prove themselves in the face of his newfound strength.
Often, characters with huge amounts of chakra are considered powerful. Naruto himself might be even more powerful in fanfiction, with his already massive chakra reaching new heights. Sasuke could also be a top - tier character, his Sharingan combined with a large chakra reserve making him a force to be reckoned with.
It might also be some of the existing characters who have turned evil. For example, Sasuke could be corrupted by a dark power and become an antagonist again. His newfound dark powers could rival Naruto's, leading to some epic battles between the two former friends.