One possible plot could be that Naruto discovers a hidden power within himself that unlocks the Rinnegan. This new power could make him face new and even more powerful enemies. He might have to learn to control the Rinnegan's abilities, which are different from his normal chakra powers. For example, the Rinnegan can allow for space - time manipulation. Naruto would struggle at first, but with the help of his friends, he would gradually master it and use it to protect the Hidden Leaf Village from a new threat that only the Rinnegan - powered Naruto can defeat.
In a Naruto with Rinnegan fanfiction, the plot could involve Naruto getting the Rinnegan through some sort of ancient ritual or curse. As a result, the other villages might see him as a threat and try to take him out. Naruto would then have to prove that he's still the same person and that he'll use the Rinnegan for good. He could use it to understand the pain of his enemies better, since the Rinnegan is often associated with seeing the truth of things. This would add a new layer to his character development as he tries to maintain peace in the ninja world while having such a powerful and feared dojutsu.
The plot could involve Naruto being sent to an alternate dimension where the blue Rinnegan is a common power among a group of powerful beings. There, he has to learn to use his blue Rinnegan to survive and also to find a way back home. Along the way, he meets different characters who teach him unique ways to harness the power of the blue Rinnegan, and he returns to his world with new skills and knowledge.
The fanfiction could involve Naruto's Golden Rinnegan being the key to a long - lost prophecy. He might find out that his new - found power is the only thing that can stop an ancient evil from awakening. Along the way, he would have to learn how to use the different abilities of the Golden Rinnegan, like being able to see the true intentions of people just by looking at them, which would help him in making allies and avoiding traitors.
The plot could start with Naruto suddenly awakening both the Mokuton and Rinnegan. He is confused at first but quickly realizes the potential. He could use the Mokuton to terraform the land, creating fertile areas for farming in war - torn regions. With the Rinnegan, he might be able to communicate with the spirits of past Hokages in a new way. This leads to him uncovering secrets about the ninja world that were long forgotten. He then uses this knowledge and his powers to bring about a new era of peace, where the different ninja clans work together more harmoniously.
Well, it might be the result of a powerful curse or a blessing from a god - like being. In the Naruto universe, there are many powerful entities. If one of them decided to bestow this unique power on Naruto, it could lead to the development of the red Rinnegan. Another idea is that it could be a side - effect of a new jutsu he tries to master. Some jutsus have unforeseen consequences, and this could be one of them.
A third plot idea is that Naruto is given the Rinnegan as a last resort to save the ninja world. An old sage or some kind of divine being bestows it upon him. But with the Rinnegan comes a prophecy that he will either save or destroy the world. Naruto then has to battle his inner demons as well as external foes, all while trying to understand the true nature of the Rinnegan and its place in his destiny.
One possible plot could be that Naruto somehow gains the Rinnegan and in his adventures, he meets Yugito. They might team up to face a new and powerful enemy threatening the ninja world. Naruto's Rinnegan abilities could give them an edge in battles, like being able to use powerful space - time ninjutsu to outmaneuver their foes. Yugito, with her own unique abilities, would complement Naruto's skills.
Another plot could be that the Rinnegan was secretly implanted in Naruto by an enemy as part of a long - term plan to turn him evil. Naruto then has to struggle not only with the new power but also with the dark influence it tries to exert on him. His friends initially suspect him, but he has to prove that he's still the same Naruto while also trying to figure out how to get rid of the Rinnegan's negative effects.
One plot idea could be that Naruto discovers the Tomoe Rinnegan during a new and powerful enemy encounter. With this new eye power, he gains abilities like enhanced space - time manipulation and can see the chakra flow in a more detailed way. This changes his fighting style and makes his enemies struggle to adapt.
A possible plot could be that Naruto, with his Rinnegan and Mokuton, is seen as a threat by some of the more traditional ninja clans. They form an alliance against him, but Naruto uses his powers in creative ways to show them that he only wants to use them for good. For example, he uses the Mokuton to create a beautiful forest in the middle of a desolate area, and uses the Rinnegan to heal some of the injured ninjas from the clans that oppose him, winning them over in the end.
One possible plot could be that Naruto with the Rinnegan discovers a parallel dimension where Haku is female. They might initially be at odds as Naruto is suspicious of this new version of Haku. But as they face common enemies in this dimension, they start to form an alliance. Haku could teach Naruto some unique ice - based jutsu that she has developed in this different world, and Naruto in turn helps her understand the power of the Rinnegan.