Well, he'd bring his unique ninja skills. His shadow clone jutsu could be super useful for various tasks on the ship, like handling multiple chores at once. And his rasengan could be a powerful attack against any strong enemies they face. Also, his never - give - up attitude would fit right in with the Straw Hats' spirit.
Well, it could be really interesting. There would probably be a lot of initial distrust from the Straw Hats, since they are usually against the Marines. But if the OC has a good heart and a strong reason for leaving the Marines, like disagreeing with their corrupt ways, the Straw Hats might gradually accept them. The OC could bring in some unique skills and knowledge about the Marines' operations, which could be useful for the crew in various situations, like getting out of tight spots when facing other Marine forces.
He might become more relaxed. The Straw Hats are a very laid - back and fun - loving crew compared to Law's more serious group. So, being around them, Law could start to crack jokes more often and not be so uptight all the time. For example, he might start to participate in Usopp and Luffy's silly games on the ship.
If Naruto was raised by the Straw Hats, he'd probably be a very different person. He might be more carefree like Luffy. For example, he'd be used to the wacky adventures on the Grand Line. His ninja skills could blend with the pirates' combat styles, creating some really unique fighting techniques.
It could be Chopper. Since Chopper is a doctor and Reiju has some medical knowledge, they might bond over sharing medical techniques and treating the crew's injuries. Also, Chopper's kind - hearted nature would make him a great friend for Reiju who might be used to a more cut - throat family environment.
Well, as of the latest manga chapters, Yamato has indeed become a part of the Straw Hats. This decision brings new dynamics and adventures to the crew.
His personality would become more outgoing and adventurous. The Straw Hats' lifestyle is full of exploration, so Naruto would be more eager to take risks.
Well, one possibility is that Reiju could bring her unique skills like her combat abilities or her knowledge of certain technologies to the Straw Hats. Maybe she joins them to seek adventure away from her family's influence. She could also form interesting relationships with the crew members, for example, having a sister - like bond with Nami due to their shared intelligence in different areas.