One idea could be an OC Hatake who has a unique chakra ability. For example, they can manipulate ice in a way that's different from Haku. They could use this to create ice sculptures that come to life in battle. Another plot could involve the OC Hatake being a long - lost relative of Kakashi. This would bring in a lot of family - related drama and secrets to uncover. A third idea is that the OC Hatake has a special bond with animals, like being able to communicate with wolves, which is rare in the Naruto universe.
One idea could be that Hatake Kakashi somehow transfers his Sharingan to Naruto in a dangerous mission. This would give Naruto new abilities and a whole new set of challenges to face. He'd have to learn to control the Sharingan quickly while also dealing with the enemies who might target him specifically for it.
Maybe an OC from a different village who is sent on a mission with Kakashi. Their different backgrounds and skills create an interesting dynamic during the mission. For example, the OC could be a master of water jutsu and Kakashi has to adapt his combat style to work with them.
One idea could be an OC who is a new ninja in the village and Kakashi becomes their mentor. The fanfic could explore their training sessions and how the OC grows under Kakashi's guidance.
The OC could be a descendant of a powerful clan that was thought to be extinct. Their presence in the Naruto world stirs up interest among many characters. The OC's knowledge of ancient jutsu and their kind heart draw in characters like Kakashi, Shikamaru, etc. into a harem. The OC then has to navigate the complex relationships while also trying to keep their clan's secrets safe.
One idea could be that the OC, reborn as Naruto, uses their prior knowledge to quickly master jutsu. For example, they might know about the Rasengan from the start and be able to perfect it faster. Another plot could involve the OC changing the relationships in the village. Maybe they befriend Sasuke earlier and prevent his defection. Or they could introduce new ninja techniques from their past life to the Hidden Leaf.
One idea could be that the OC team is on a mission to retrieve a rare and powerful ninja artifact that has been lost for centuries. This could lead to battles with other ninja clans who also want the artifact.
Another plot could involve an OC reborn into the body of a criminal in the Naruto world. They have to struggle to redeem themselves and prove that they are not the same person as the original criminal. Along the way, they could discover the real reasons behind the original criminal's actions and try to right the wrongs that were committed.
One idea could be an OC who is a time - traveler from the future. They come back to the Naruto world to prevent a great disaster that they know will occur in the future. This OC could have unique powers related to time manipulation or future - sight.
One idea could be an OC Senju who has a unique ability related to plant manipulation, like being able to make plants grow rapidly into defensive or offensive structures. Another could be an OC Senju who is a healer and has to deal with the aftermath of a big battle in the Naruto world. Maybe an OC Senju who is on a quest to discover a long - lost Senju clan jutsu that was forgotten over time.
One idea could be that the OC is reincarnated as a member of a powerful but long - lost clan in the Naruto world. They then have to discover their clan's secrets and powers while also dealing with the ongoing conflicts in the shinobi world. For example, they might find a unique jutsu that was lost with their clan.