For Mokuton, Naruto may have the ability to create wooden clones, which would be different from his regular shadow clones. These wooden clones could be stronger and more durable. Regarding the Rinnegan, he could gain the power of the Preta Path to absorb chakra attacks. He could also use the Animal Path to summon powerful creatures. In a demon fanfiction, these abilities would be really useful against demons and other foes.
Well, Mokuton would enable Naruto to create complex wooden structures. He could build entire fortresses out of wood in the blink of an eye. As for the Rinnegan, he might unlock the power of the Human Path, which could let him read minds or extract information from enemies. He could also use the Naraka Path to create illusions of hellish landscapes to intimidate his foes. In a demon - themed fanfiction, all these abilities combined would make Naruto a very formidable force against the demonic threats.
With Mokuton, Naruto could grow trees instantly for various purposes like creating shelters or using them as weapons. And with Rinnegan, he might be able to use the Deva Path to control gravity, push or pull enemies. He could also use the Asura Path to create mechanical arms or other body parts for enhanced combat.
One possible main antagonist could be a rogue ninja who also has a connection to the Mokuton or Rinnegan powers. Maybe he was once part of a secret experiment that went wrong and now he wants to take Naruto's powers for himself. Another option could be an ancient being that was sealed away long ago and is now awakened by Naruto's new powers. This being could see Naruto as a threat to its plans of world domination.
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.
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 changes the story a great deal. First, the Mokuton gives him an edge in combat as he can manipulate plants and wood. This could be used in creative ways like creating huge forests to trap enemies or using wooden constructs for offense. The Rinnegan, on the other hand, is a whole new level of power. He could potentially use it to travel between dimensions, which would open up new plotlines. For example, he could discover new threats or allies in other dimensions. Overall, his character would become more complex as he tries to master these new powers.
With the Rinnegan, he could have abilities like the Six Paths techniques. He might be able to use the Preta Path to absorb chakra attacks. And with the Hyoton, he could create ice - based jutsu that are much more powerful than normal ice jutsu, like freezing an entire area instantly.
He could have the ability to use all six paths techniques right from the start. This means he could manipulate gravity like the Deva Path, absorb chakra like the Preta Path, and even revive the dead like the Outer Path.
He could gain the ability to create large - scale wooden structures, like Hashirama did. For instance, he could build huge wooden golems to fight for him in battles.
A fanfiction could center around a battle between two powerful ninjas, one who has mastered the Mokuton and Sharingan, and the other who has the Rinnegan. The fight could be not just about physical combat but also about the clash of different ideologies related to these powers. The one with the Mokuton and Sharingan might believe in a more traditional view of power, while the Rinnegan user could have a more radical view.
One plot idea could be a story where Naruto discovers he has the Mokuton and Rinnegan abilities due to some ancient curse or prophecy. He then has to learn to control these new powers while facing off against a new, powerful enemy that is immune to normal jutsu. Another idea is a fanfic where Naruto uses his Mokuton and Rinnegan to travel to different dimensions to find a way to save the Hidden Leaf from a looming disaster. Or perhaps a story where he has to team up with old enemies who are also intrigued by his new powers and together they form an uneasy alliance to fight a greater evil.
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.