One plot idea could be Naruto using his wings to rescue the girls in his harem from various dangerous situations. For example, he might fly them to safety when their village is under attack. Another could be that the wings are a symbol of a new power he has gained, and the girls in the harem are drawn to him because of this unique power.
One plot idea could be that Naruto is summoned to a different dimension where ninjutsu doesn't exist. He has to adapt and use his raw strength and wits to survive and find a way back. Another could be that he's summoned by an ancient clan that believes he's the key to unlocking a powerful, long - lost jutsu. They force him to help them, but Naruto tries to find a peaceful solution instead of just following their orders.
One plot idea could be that Naruto is framed for stealing a powerful and ancient scroll from the village. The real culprit could be a rogue ninja who has the ability to disguise as others. Naruto then has to prove his innocence while on the run from the village's forces. Another idea is that he's framed for a crime that was actually committed by a corrupt member of the village council, who wants to get rid of Naruto because he's seen as a threat to their power.
A plot could also involve Naruto being reincarnated at a different point in the Naruto timeline. For example, if he was reincarnated during the time of the Sage of Six Paths. He could have a major impact on the early development of ninjutsu and the ninja world.
One idea could be that Naruto discovers he has the power to manifest angel wings. This new power could make him an outcast at first, as it's so different from his normal ninja abilities. People might fear or envy him. But then he uses these wings to save the village in a unique way, like flying above to spot an approaching enemy army early.
A really cool plot idea would be that Naruto is part of a prophecy where the one with bat wings will save the ninja world from a new, flying - based threat. His bat wings give him unique abilities in combat, like the ability to perform aerial acrobatics that no other ninja can. He has to train hard to master these new skills. His friends initially might be a bit shocked but then support him as he embarks on this new adventure to protect the world.
One plot idea could be that the apprentice has a special power that Merlin has to help them control. For example, the apprentice can see the future in dreams but it's jumbled and Merlin uses his magic and wisdom to teach the apprentice how to make sense of it. Another idea is that the apprentice is from a different land with different magical practices, and they clash and then blend with Merlin's teachings. A third idea could be that the apprentice is initially a skeptic of magic but Merlin shows them the beauty and necessity of it through various adventures.
One idea could be that Naruto, with his ninja skills, gets transported to Starfire's universe. There, his unique abilities draw the attention of many characters, leading to the formation of an accidental harem. For example, his ability to make shadow clones might be seen as a very useful and cool power. Another plot could involve a common enemy that forces Naruto and Starfire, along with other characters who are part of the harem, to work together. This could lead to some interesting dynamics as they all come from different backgrounds and have different ways of fighting.
One idea could be that a Saiyan character somehow ends up in the Naruto universe and due to their unique powers, attracts a harem. For example, they might save a group of ninja from a powerful enemy using their super strength and speed, and the ninja, both male and female, become intrigued by this new and powerful being.
One idea could be that Naruto and Deadpool end up in a strange multiverse situation where they meet various female characters from their respective universes. They then have to team up to protect these females from a common enemy, and in the process, a harem - like dynamic forms as the female characters develop feelings for them.
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.