Well, in some fanfictions, he might obtain it through a strange encounter. Maybe he stumbles upon an ancient relic during a mission that contains the power of the broken eye dojutsu and it somehow bonds with him.
It might have the ability to see through illusions that normal eyes can't. Since it's a dojutsu, even if it's broken, it could still have some enhanced visual powers. For example, it could detect the tiniest movements of an enemy, giving Naruto an edge in combat.
Perhaps it's a dojutsu that can manipulate the elements in a new way. For instance, it could turn his wind - style jutsu into something more powerful and less predictable. It might also have the ability to absorb the chakra of his opponents when he makes eye contact with them, which would give him an edge in battle. The appearance of the dojutsu could be something like a swirling pattern in his eye.
In some fanfictions, Naruto might obtain all dojutsu through some kind of ancient inheritance. Maybe he discovers a long - lost scroll or a hidden temple that bestows upon him these powerful eye techniques.
Well, it could enhance his combat a great deal. With a dojutsu, he might gain abilities like enhanced perception, allowing him to predict his opponents' moves more accurately. It could also give him some sort of elemental boost, like better control over his existing jutsu or even access to new ones related to the dojutsu's nature.
Well, one way could be through some super - rare and powerful jutsu that transfers the dojutsu abilities to him. Maybe a forbidden jutsu that was long forgotten but he stumbles upon it somehow.
Often, the unique feature is the new power dynamic. Naruto having a dojutsu changes the way battles play out. For example, in many of these fanfics, he can see things others can't, like hidden traps or chakra flow, which gives him an edge in combat.
He could get a Dojutsu that allows him to manipulate time. This would be a very powerful ability as he could slow down or speed up time during battles. For instance, he could slow down time to dodge an enemy's attack and then speed it up to counterattack.
Well, it could make him an even more powerful ninja. The Dojutsu might give him new abilities like enhanced perception, the ability to see chakra more clearly, or even some kind of special attack. For example, if it's a Dojutsu similar to the Sharingan, he could potentially copy jutsu more easily.
The balance in the ninja world would be completely disrupted. Allies might start to fear him as well. Naruto would have to be very careful about how he uses his powers to avoid causing chaos. He might also face moral dilemmas. For example, some of the dojutsu might give him abilities that could be considered unethical if misused, like mind - control - like powers. So he'd need to figure out the right way to use all these new powers.