In fanfiction, if Naruto was born in One Piece, he could bring a new style of fighting. His speed and agility from being a ninja would give him an edge in combat. He could run across the masts of pirate ships like he runs on trees. His Sage Mode could be related to some kind of ancient knowledge in the One Piece world. And his strong willpower would fit right in with the characters in One Piece who often have to face great challenges. He might even inspire some of the characters to be more selfless in their pursuit of their dreams.
One possible plot could be that Naruto, through some sort of magical or cross - dimensional event, ends up in the One Piece world. His ability to control the ocean could startle the pirates and marines alike. Maybe he teams up with the Straw Hat Pirates. He could use his ocean - controlling powers to help them navigate through dangerous waters, like the Calm Belt. He might also use it to fight against powerful enemies, like the Yonko, by creating huge tidal waves or whirlpools.
If Naruto was born the same age as Itachi in fanfiction, it would change the power balance in the village. Naruto could be part of the decision - making processes earlier. His influence on the Uchiha clan's fate might be significant. He could use his unique ability to persuade and his strong will to try and bridge the gap between the Uchiha and the village. Also, his interactions with Kakashi would be different. Instead of Kakashi being an older, more experienced mentor, they could be more like comrades or even rivals in some aspects.
Well, one possibility is that he'd have the Sharingan from the start. He might grow up with different training methods, more focused on Uchiha techniques. Maybe he'd be more of an outcast in the village not just because of the Nine - Tails, but also because of the Uchiha's reputation. And his relationship with Sasuke would be completely different, perhaps they'd be rivals in a whole new way, competing over who is the true Uchiha heir in terms of power and abilities.
Well, one possibility could be that Naruto is born into the Yamanaka family instead of being an orphan. He might grow up with their unique abilities and family traditions. For example, he could learn their mind - related jutsu much earlier and use it in a creative way during his ninja training. Maybe he'd have a different relationship with Ino and the other Yamanaka members, and this could lead to a whole new set of adventures and challenges within the Naruto universe.
In a 'Naruto born in RWBY' fanfiction, the plot could involve Naruto being born into a family in Remnant. He would likely face the unique challenges of that world. For example, he could attend one of the Huntsman academies. Since he's used to training hard, he'd probably be a top student. His ability to sense danger, which he has from his ninja training, would be very useful in a world full of Grimm. He might also introduce some new fighting styles to the RWBY universe.
The plot might also involve Naruto having to deal with the expectations of the Nara clan. Since they are known for their intelligence and strategic thinking, Naruto would need to develop these skills quickly. This could lead to some interesting interactions with characters like Shikamaru. Maybe Naruto would be in competition with Shikamaru to prove himself as a worthy Nara, which in turn could change their friendship dynamic.
Well, Naruto's chakra - based abilities would be quite unique in the One Piece world. His Rasengan, for instance, would be a powerful new type of attack that most characters in One Piece haven't seen. His ability to walk on walls and water using chakra would also give him an edge in many situations. He might also be able to use his chakra to sense things in a different way than the Haki users in One Piece, which could be a big advantage when exploring islands or looking for hidden treasures.
If Naruto were born in the High School DxD fanfiction universe, there would be a lot of potential storylines. Naruto's Uzumaki heritage could give him an edge in a world full of different supernatural beings. His ability to make friends and his sense of justice would likely lead him to get involved in the various conflicts in the DxD world. He could also introduce the concept of ninjutsu to this world. His training methods might be adopted by some of the characters there, and he could even start his own ninja - themed group within the DxD setting.
If Naruto was born in the One Piece world, he would probably be a very unique individual. His ninja skills like shadow clones could be a huge asset. Maybe he'd join a pirate crew and use his skills to fight against the Marines or other pirates. His determination to be recognized, similar to his goal in the Naruto world, would likely drive him to achieve great things in the One Piece universe as well.
Perhaps in this fanfiction, Naruto being born an Uchiha means he has a natural rivalry with Sasuke from the start. Since they both have Uchiha blood, they might compete not just for power but also for the right to be the true heir of the Uchiha legacy. Also, his Uchiha lineage could attract the attention of Orochimaru, who might see Naruto as a new vessel with the potential of the Uchiha powers.