The Straw Hat crew would probably be very surprised at first. Nami might worry about how Hancock's presence would affect their finances, since Hancock is used to a more luxurious lifestyle. Usopp would be in awe of Hancock's beauty and powers. Chopper would be excited to have Hancock around, as she could potentially teach him about different kinds of medicine from Amazon Lily. Zoro might be a bit skeptical at first but would come to accept it as long as Luffy was happy.
The Straw Hat crew would be in for a big shock at first. But then they would quickly rally around Luffy and Nami. Robin might offer her wisdom on raising a child and share stories from her own past. Franky would build amazing things for the baby like a super - safe crib or a high - tech stroller. Brook would play music to soothe the baby. And they would all work together to make sure the baby has a great life on the ship.
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.
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.
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.
In fanfiction, if Ace joins Luffy's crew, it would be an amazing addition. Ace's powerful fire abilities would make the crew even stronger in battles. He could also bring a different dynamic to the group, as he has his own personality and backstory. His relationship with Luffy would be a central focus, and we might see more brotherly bonding moments on the ship.