One plot idea could be that Naruto loses an eye in a fierce battle against a new, powerful enemy. He then has to adapt his fighting style, perhaps learning new jutsus that rely more on his other senses. Another idea is that he discovers a hidden power within his one eye, like a unique form of the Sharingan that was dormant until the loss of his other eye. Or maybe he gets an artificial eye with special abilities given to him by a mysterious ally.
A possible plot could be that Naruto is cursed and his one eye starts to show visions of the future. This makes him a target as various factions want to use his ability for their own gain. He has to struggle to control the visions and keep himself safe while still trying to protect the village. Also, his friends might be suspicious of him at first because of the strange power in his one eye.
One plot idea could be a character who is an experiment and has only one Sharingan eye implanted. They struggle to control its power and are hunted by those who want to use their unique situation. For example, they might have to constantly fight off rogue ninjas who think they can steal the eye's power.
One plot idea could be a character who was born with only one Sharingan eye and has to struggle to master its powers in a world where most Uchiha have two. They might face discrimination from their clan for being different. Another idea is that a character loses one of their eyes in a battle and then has to adapt to having just one Sharingan, with different abilities emerging as a result of this change. For example, the single Sharingan could have enhanced perception abilities to make up for the lack of a second eye.
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.
A really cool plot could be that the eye elders are actually the protectors of a secret prophecy related to Naruto's eye power. They have been waiting for the right time and the right person to fulfill this prophecy. Along the way, they face challenges from other villages who want to get their hands on this prophecy. This would involve a lot of political intrigue and power struggles, much like what we often see in the Naruto series.
Another plot could revolve around how he copes with the loss of vision in one eye during his battles. He might have to develop new fighting techniques. Maybe he teams up with a magical creature that can act as his 'extra eye' in a sense, guiding him during duels. This could also lead to a deeper bond between him and the creature.
One interesting concept could be a crossover where Odin's power in some way influences Naruto's ninja world. Maybe Naruto gains some of Odin's wisdom or a unique jutsu related to Odin's magic. For example, Odin's one eye could hold a special power that Naruto has to learn to control to defeat a new, powerful enemy.
One idea could be a character having the 'All For One' quirk in the Naruto universe and using it to steal other ninja's unique abilities. For example, they might target a Sharingan user to gain that power. Another plot could involve a group trying to stop this 'All For One' - like - character from disrupting the balance of power in the ninja world. And perhaps the character with 'All For One' has a hidden motive related to an ancient prophecy in the Naruto world.
Well, a really cool plot might be that Orochimaru, always interested in new powers, somehow gets his hands on the 'All for One' concept. He could start using it to assimilate the powers of different beasts, like the tailed beasts, in a new and different way than just sealing them. Or perhaps a young genin discovers they have the 'All for One' ability. They initially use it to help their friends by taking on some of their weaknesses, but then it attracts the wrong kind of attention from the Akatsuki, who see it as a powerful tool for their own goals. Also, a time - travel plot where a character from the future with the 'All for One' ability comes back to the Naruto world to change the course of history, either for good or bad.
One idea could be exploring the relationship between Naruto and the One Tail's spirit. Maybe they can communicate in a dream - like state, and the One Tail gives Naruto some unique insights about his power and his role in the ninja world.
Well, a great plot for Blue Eye Samurai fanfiction could involve her facing a new and powerful enemy that has a personal vendetta against her. This enemy could be a former ally turned bad. Also, you could write about her training a new generation of warriors, passing on her skills and wisdom. And she might get involved in a political intrigue within the samurai world that tests her loyalty.