He might gain enhanced perception. This could allow him to see chakra flow more clearly, similar to how the Sharingan can. So in battles, he can anticipate his opponents' moves better.
Perhaps the awakened dojutsu gives Naruto the power to see into the future briefly. This would be a huge advantage in combat. He could foresee an opponent's attack and counter it before it even happens. In the context of the Wave fanfiction, this new ability could also help him in making strategic decisions for the village. He could see potential threats coming and take preventive measures.
Well, it could be a dojutsu that gives him the ability to manipulate elements in a new way. For example, he could combine fire and wind chakra in a more efficient and powerful manner than before. In the story, this new power could be the key to defeating a powerful enemy in Wave. Maybe he uses it to protect his friends from a dangerous villain who has been causing chaos in the village near Wave.
He becomes more confident. Knowing he has this new power from the dojutsu makes him believe more in his abilities to face tough challenges.
It could be a water - based kekkei genkai. Since the Wave arc has a lot to do with water, it would make sense for Naruto to awaken a kekkei genkai related to water. This could give him an edge in battles, especially in the Wave region where water is abundant.
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.
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, 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.
With the Rinnegan, Naruto might gain the power of the Human Path. This would allow him to read minds or rip out souls, which is a very dark and powerful ability that would be quite different from his usual positive - natured powers.
It might be related to a connection with some powerful entity in the Wave arc. For example, if there's a secret shinobi from the past whose power is tied to the Rinnegan and Naruto somehow forms a bond with that power source, it could lead to the awakening. Also, the intense emotions and challenges he faces in the Wave arc might be a catalyst, pushing his chakra to a new level and awakening the Rinnegan.
One implication is that he becomes much more powerful. The Rinnegan gives him access to powerful abilities like the Six Paths techniques, which would change the power dynamics in battles in the fanfiction. He could now face stronger enemies more easily.
Maybe it has something to do with his Uzumaki heritage. The Uzumaki clan was known for their strong chakra, so it could be a latent ability passed down through the generations.
One possibility is that there's some ancient chakra or energy in Wave that interacts with Naruto's own chakra. The unique environment of Wave, with its water and nature elements, might have caused his Mokuton to awaken. Another reason could be that Naruto has some kind of connection to the First Hokage that gets revealed during the Wave mission, and that connection enables the Mokuton awakening.