In a fanfiction where Naruto is a fishman in One Piece, Naruto would face new challenges. For example, dealing with the discrimination that some fishmen face in the One Piece world. But he'd also have new opportunities. He could use his fishman physiology to swim faster and deeper, discover hidden treasures, and maybe even find a way to connect the ninja world with the pirate world. His Nine - Tailed Fox chakra might also have some interesting interactions with the strange powers in One Piece.
The One Piece system could change the relationships between characters. Heroes and villains who previously had no connection might be brought together because of the new elements introduced by the system. For example, the X - Men might have to team up with a group of characters inspired by One Piece pirates to face a common threat that the One Piece system has brought into the Marvel world. This could lead to new storylines and character developments as they learn to work with different personalities and power sets.
Madara's powers would be both a boon and a bane in the One Piece fanfiction world. His ability to summon the Susanoo could be a fearsome sight on the Grand Line. It could be as intimidating as some of the giant sea kings or even the ancient weapons. On the other hand, his powers might not be fully understood by the characters in One Piece. For instance, the concept of chakra is different from Haki and Devil Fruits. But if written well, his presence could add a whole new layer of excitement and mystery to the story. Maybe he could form alliances with some of the Yonko or even oppose them, depending on the plot of the fanfiction.
Kankuro could use his puppet - making skills to his advantage. He could create puppets that are resistant to the elements in the One Piece world, like water - proof puppets since there are a lot of sea - related challenges there. Also, he could make puppets that can fly to deal with the various islands and different terrains.
He might fit in as a sort of super - strong outsider. Vegeta could be on a quest for his own kind of 'One Piece', which could be something related to power or a way to return to his own universe. His Saiyan abilities would make him a force to be reckoned with. For example, his ability to transform into Super Saiyan forms would be like a new level of power that no one in the One Piece world has seen before. He might start out as an antagonist but could end up teaming up with the Straw Hats if they had a common enemy.
In the Marvel world, a One Piece system could potentially introduce unique power concepts like Devil Fruits. For example, a character might gain the power of the Gomu Gomu no Mi, which would give them rubber - like abilities similar to Mr. Fantastic but with a more One Piece - style flavor. It could also bring in the concept of Haki, which could be a new form of energy or awareness in the Marvel universe, allowing characters to sense danger or overpower opponents in a different way.
Sakura would fit in as a strong fighter. Her physical strength and combat training from being a ninja would make her a formidable opponent in the pirate - filled world of One Piece. She could hold her own in battles against pirates or other threats.
Naruto could fit in by using his physical abilities. His superhuman strength, speed, and endurance, which he developed through his ninja training, would make him a formidable opponent in the One Piece world. He could easily take on weaker pirates or even some of the lower - level Marines.
Sasuke's character could potentially bring a new level of intensity to the One Piece world. His Sharingan abilities, like seeing through illusions and predicting movements, might make him a formidable opponent. He could be a lone wolf type of character in the Straw Hat crew, initially aloof but gradually warming up to the others, much like Zoro in some ways.
The significance of 'one piece the story' lies in its ability to capture the imagination. It has created a vast and detailed world with different islands, each having its own culture and secrets. The characters in the story, from Luffy's determination to Zoro's loyalty, are what make it so special. It's not just about finding the treasure but also about the growth of the characters along the way. It has inspired generations of anime fans with its epic scale and engaging plot.