Well, it could be that the wielder of the Rinnegan has the ability to control powerful forces like the Six Paths techniques. They might use the Deva Path to create massive gravitational pulls that start to crumble the buildings in Konoha. Or perhaps with the Preta Path, they could drain the chakra from all the ninja in Konoha, leaving them defenseless against further attacks, which eventually leads to the destruction of the village.
Well, it changes drastically. The Rinnegan is one of the most powerful dojutsu in the Naruto universe. When Naruto has it along with Hyton, he can probably use the Rinnegan's power to enhance his existing Rasengan techniques. And with Hyton, he could add an ice - based element to his attacks. This would make him a formidable opponent against even the strongest of enemies.
His power level would skyrocket. The Rinnegan has a vast array of abilities. Naruto already has a huge amount of chakra from Kurama. When combined with the Rinnegan, he could use the Rinnegan's techniques to enhance Kurama - related attacks. For example, he might be able to use the Preta Path to absorb chakra while in his Kurama - enhanced form. This would not only make him stronger in battle but also more versatile as he could counter different types of opponents more effectively.
Some would be in awe. The villages that Naruto has helped in the past would likely see it as another sign of his strength and a great asset. For example, the Hidden Leaf Village would feel even more protected. However, the other villages that have been enemies or rivals in the past might see it as a threat and start to plot against Naruto and the Leaf Village.
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.
Well, it would significantly boost his power. The Rinnegan is an extremely powerful dojutsu. Naruto already has his vast chakra reserves and Sage Mode. With the Rinnegan, he could gain new abilities like the Six Paths techniques. He might be able to manipulate gravity, use the Outer Path to revive the dead (though this has its own moral and plot implications in the fanfiction world). His combat capabilities would be off the charts, making him one of the most formidable characters in the fanfiction universe.
It could completely change the power dynamic in the story. Naruto with the Rinnegan would likely become almost invincible, making his battles much less challenging.
The power system would likely become extremely complex. With the Rinnegan's six paths abilities and the Sharingan's unique powers like genjutsu and precognition combined, the character might gain new forms of ninjutsu. For example, they could use Sharingan - enhanced genjutsu within the framework of Rinnegan - based reality manipulation. It could also lead to a new tier of chakra control and power output that far exceeds what we've seen in the original Naruto series.
It could be that he was in a life - or - death battle against a powerful enemy. Maybe he was pushed to his limits, and in that moment of extreme stress and desperation, his latent power awakened in the form of the Rinnegan.