It could also be that instead of fighting right away, there's a tense stand - off. Luffy, remembering Ace's past encounters with Blackbeard, would be full of anger and distrust. Blackbeard, on the other hand, might try to taunt Luffy, trying to get him to make a rash move. The situation could escalate slowly as they exchange words, with their crews on edge, waiting for the first sign of action.
Well, in such a fanfiction, Ace might be worried about Luffy. Since Blackbeard is a dangerous character. He could decide to go and find Luffy to protect him. Maybe he'd start looking for Blackbeard too, to make sure he doesn't harm his little brother.
Blackbeard's crew is also a diverse bunch. His more aggressive members like Burgess might be eager to start a fight with Luffy's crew. However, some of the more cunning members could be thinking of ways to use the situation to their advantage. They might try to manipulate Luffy or his crew into making mistakes. And if Blackbeard decides on a certain course of action, his crew would generally follow, but there could be some internal dissent depending on the situation.
Ace would probably be angry at first. He doesn't want Luffy getting involved with such a dangerous person like Blackbeard.
In this kind of fanfiction, Ace might take Luffy on an adventure to find a hidden treasure. They could encounter various powerful enemies and strange islands along the way.
Well, in this scenario, Luffy's crew would surely go all out to rescue him. Nami might come up with a clever plan using her navigation skills and knowledge of the area where Doflamingo is likely to be hiding Luffy. Zoro would be ready for a fight, his swords sharp and his determination unwavering. They might also get some unexpected help from other characters in the One Piece world who have a grudge against Doflamingo.
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.
One possibility is that they would first be confused by each other's strange abilities. Naruto with his jutsus, and Luffy and Sabo with their Devil Fruit powers. But then they might find common ground in their strong sense of loyalty and friendship. They could team up to fight against a common enemy, perhaps some powerful pirates or shinobi who are causing chaos in both their worlds.
In this fanfiction, Naruto might use his shadow clone jutsu to create distractions while he rescues Luffy and Ace. His speed and combat skills could prove crucial.
In a fanfiction where Luffy turns into a girl, the story could take an interesting turn. Luffy's dreams of becoming the Pirate King wouldn't change, but the way he approaches it might. As a girl, he could use his charm to get out of some tricky situations. For example, when dealing with some of the more traditional pirates or marines who might underestimate a girl. Also, the Straw Hat crew's dynamic would shift. Zoro might be more protective, not that he isn't already, but in a different way. And Chopper would be super curious about the sudden change and would constantly be checking if there are any medical reasons for it, even though it's a magical fanfiction change.
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.