The crew's reaction while watching Luffy vs Katakuro in the fanfiction would depend on the situation in the fight. If Luffy starts using his Gear Fourth, the crew would be in awe. They know how powerful it is. If Katakuro manages to counter Luffy's attacks effectively, the crew would start to get more and more tense. Their reactions would also add to the overall atmosphere of the fanfiction. It would not only be about the fight between Luffy and Katakuro but also about how the crew experiences it.
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.
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.
In a 'Sabo meets Luffy crew' fanfiction, there could be a lot of emotional reunions. Sabo might share his adventures since they last parted. He could train with the crew members, especially Zoro to exchange sword - fighting skills. And he would surely have a great time reminiscing about their childhood with Luffy.
In this fanfiction, Luffy might be initially in awe of Whitebeard's presence. He could challenge one of the crew members to a friendly spar, like Ace perhaps. And they might share stories about their adventures at sea.
In the fanfiction, Hancock could offer her help to Luffy's crew. Given her strength and influence in Amazon Lily, she could provide valuable resources or information. Maybe she'd teach Nami some self - defense techniques she learned in her own island. Also, there could be some romantic tension between Hancock and Luffy that the crew might tease them about.
In this fanfiction, Ace might share his amazing adventures with Luffy's crew. He could show off his cool fire - based powers and tell stories about his time on the sea before meeting them.
In fanfiction, when Shanks meets Luffy's crew, it could be a very emotional reunion. Shanks might be impressed by how much Luffy and his crew have grown. He could see the strong bonds within the crew and be proud of Luffy for leading them so well.
Well, in this kind of fanfiction, one possibility is that the Gotei 13 members might be amazed by Ichigo's growth. They could see his new powers and techniques during the fight with Ulquiorra. Maybe they would start to respect him more as a true force to be reckoned with in the Soul Society.
Well, his parents might be a bit shocked at first. I mean, Luffy's crew is full of such unique characters. They could start by testing the crew's loyalty to Luffy. And then, they might offer some valuable advice or even some special training. Like, if his father has some unique skills, he could pass them on to the crew to make them even stronger for their future adventures.
Perhaps the Fairy Tail members watching will have different reactions. Some might be worried for Natsu, especially those who are close to him like Lucy or Happy. Others, like Erza, might be more focused on analyzing Natsu's moves and Zero's counter - attacks. And there could be some comic relief from the likes of Gray, making snarky comments while still being engaged in the fight between Natsu and Zero.
If Naruto joined Luffy's crew in fanfiction, there would be a lot of interesting interactions. Naruto is used to a world with different kinds of powers like chakra, and in the One Piece world, there's Haki and Devil Fruits. He would have to learn about these new power systems. Also, his relationship with the crew members would be fun to explore. For example, he and Usopp could probably come up with some crazy inventions together, combining ninjutsu and Usopp's gadget - making skills.