Obviously, they will support Luffy all the way. He is their captain, and they have complete faith in him. They have been through so much together, and they know Luffy's strength and determination.
If a marine joins Luffy's crew in a fanfic, it could be quite interesting. At first, there might be a lot of distrust among the crew members. After all, they've been fighting against marines for a long time. But if the marine has a strong sense of justice that aligns with Luffy's own view of right and wrong, they could gradually be accepted. For example, the marine might bring in some new combat techniques or knowledge about the navy's operations that could be useful to the Straw Hats.
A marine who has a special ability or talent that the crew lacks. Maybe a marine who is really good at deciphering ancient texts or has a unique form of martial arts. They would be attracted to Luffy's crew because of their freedom - loving spirit. And once they join, they could use their skills to help the crew in their adventures, whether it's finding a hidden treasure or fighting against a powerful enemy.
Shanks might interact with Luffy's crew in a very friendly and father - like way. He could pat the crew members on the back, give them words of encouragement, and share his experiences with them.
A great plotline might involve the crew getting lost in a mysterious and dangerous part of the Grand Line. They have to rely on each other more than ever and discover hidden secrets about the world and themselves. Maybe they find an island that has been forgotten by time, with technology or magic that is completely different from what they've seen before. And of course, there could be a lot of character - development moments for all the crew members during this adventure.
One potential new member could be a skilled archer from a forest - dwelling tribe. They have amazing accuracy and can use special arrows made from rare materials found only in their forest. Another could be a mermaid or merman with the ability to control water in unique ways, not just for combat but also for things like navigation and finding hidden treasures.
I think it has the potential to be very engaging. A marine joining Luffy's crew would bring in a clash of ideologies and force both the marine and the crew to adapt and grow. It could lead to some unexpected plot twists and character developments.
Well, the crew would probably be on the edge of their seats. Luffy is known for his unpredictable and powerful fighting style. Katakuro, on the other hand, has his own set of unique abilities. Maybe the crew would be cheering Luffy on, shouting words of encouragement. They might also be worried at times, especially when Katakuro gets the upper hand in some moments of the fight. It would be a very intense moment for them to watch.
Well, for one thing, Naruto's experience in dealing with various types of enemies in his own world would be a great asset. He could share his knowledge of battle strategies with the Straw Hat Pirates. Also, his ability to befriend people easily, as seen in how he got along with his own comrades in Konoha, would help him gel with the crew members. Plus, his sense of loyalty is unwavering, which is a quality highly valued in Luffy's crew. The dynamic on the ship would change completely with Naruto around, as he has his own unique way of looking at things and approaching problems.