A third possible plot is that Naruto tries to bring the two worlds together. As the son of Rayleigh, he has a connection to the One Piece world. He could see the potential for the ninja world and the pirate world to co - exist and work towards a common good. However, there would be many obstacles in his way, both from those who oppose the idea of mixing the two worlds and those who want to use the situation for their own gain.
Another plot could revolve around Naruto being hunted. Maybe there are forces in both the Naruto and One Piece universes that see Naruto as a threat because of his unique heritage. He has to constantly be on the run, learning new skills along the way to defend himself. He might team up with some unlikely allies from both universes, like a One Piece character helping him understand his new powers while a Naruto character helps him with his ninja skills.
If it's a Naruto - son of Silver Rayleigh fanfiction, it might involve a lot of world - building. The author would have to figure out how to blend the Naruto and One Piece universes. Naruto might grow up with a different set of values, influenced by Rayleigh's pirate ways. He could be more of a lone wolf, yet still hold onto his original Naruto - like determination to protect his friends and village. It could also lead to some really cool fight scenes where Naruto combines his ninja techniques with Rayleigh - inspired powers.
One potential plot could be Naruto having to prove himself to the Green Lantern Corps. They might not trust him at first because he's from a different world. Another could be Naruto using the Green Lantern powers to protect Konoha from a new, super - powerful enemy that normal ninja techniques can't defeat.
A possible plot might be that Harry uses his Superman - like powers to help the wizarding world during times of peace as well. For example, he could use his super strength to rebuild parts of Hogwarts that were damaged in previous battles. Or he could use his flight to quickly transport important magical artifacts from one place to another. Also, there could be a plot where the wizarding community is initially afraid of Harry because of his non - magical powers, but he has to prove that he is still one of them and is there to protect them.
A potential plot could be Percy being sent on a special mission by Zeus. This mission might be crucial for the balance of the godly world, and Percy has to prove himself worthy of being Zeus' adopted son. He could face many obstacles and powerful foes during this mission.
One potential plot could be Naruto being turned into a vampire god against his will. He then has to struggle with his new identity and the cravings that come with it. He might try to hide it from his friends at first. Another plot could be that there is a prophecy about a vampire god saving the ninja world, and Naruto is believed to be that one. So he has to embrace his new powers and learn how to use them for good. And a third plot could be that a vampire god from another dimension enters Naruto's world and Naruto has to either defeat it or make an alliance with it.
Another plot could revolve around Naruto's relationship with Ibiki. Ibiki might have some dark secrets from his past that he slowly reveals to Naruto as they train together. Naruto would then have to deal with these revelations and how they impact his view of Ibiki and the world around him. It could be a story of trust and growth between the two.
Well, a possible plotline is that Naruto has to deal with the fact that he has the power of the Kyuubi in a more innate way. Maybe he discovers that he can access certain abilities that are unique to being the son of Kyuubi, like a deeper connection to the chakra of the nine - tailed beast. There could also be a plotline where the Akatsuki target him not just for the Kyuubi's power but because of his special connection to it as its son. And his own village might have to decide whether to protect him or sacrifice him for the greater good.
One potential plot could be Naruto struggling to control his new mini Kyuubi form. He might accidentally cause some chaos in the village while trying to figure out how to use his powers.
One potential plot could be the OC trying to learn Orochimaru's jutsu for good purposes. Maybe they want to use his knowledge of forbidden jutsu to heal people or protect the village in a way that was not thought of before.
A possible plot is that the arranged marriage is a part of a larger plan to strengthen the village's medical and ninja forces. Naruto's combat skills combined with Shizune's medical expertise could be a powerful combination. They might have to go on missions together as a married couple, which would force them to rely on each other. Also, there could be a plot where Tsunade plays a role in their relationship, either guiding Shizune or giving Naruto advice on how to be a good husband. This would add an interesting dynamic to the story.