Nami could also be a common character. She might help Luffy manage the financial aspects of his admiral duties, as well as use her navigation skills to assist in any navy - related voyages. And of course, she'd be there to keep Luffy in check when he gets too carried away.
One common character paired with 'female Luffy' is Zoro. In some fanfictions, their relationship could be more of a romantic nature. Zoro might be the first one to notice the changes in Luffy when she reveals her female side, and then they start to develop a deeper connection. Their dynamic would be different from the original, with more of a romantic tension added to their usual banter.
Some fanfictions also pair Luffy with Hancock. Given Hancock's infatuation with Luffy in the original series, it's not a stretch to develop a full - blown love story. Her powerful status as a pirate empress and Luffy's carefree nature can create an interesting dynamic, with Hancock trying to win Luffy's heart while he is mostly oblivious to her romantic intentions.
One interesting plot could be Luffy in an alternate universe where he becomes an admiral earlier in his journey. He might use his unique leadership style and devil fruit powers in new ways to uphold the navy's justice while still maintaining his core values of freedom and friendship.
Aside from Luffy, characters like Ace might show up in this type of fanfiction. Ace, being Luffy's brother, could have some connection to Luffy's discovery of conquerer's haki, perhaps through memories or some form of spiritual guidance. Additionally, some powerful enemies might be present. These enemies would serve as the motivation for Luffy to quickly master the conqueror's haki in order to defeat them and protect his crew. There may also be some minor characters from the One Piece world who assist Luffy in his learning process, like the inhabitants of a special village that has knowledge about haki.
Well, one unique feature is the role - reversal or role - expansion. Luffy, who is known for his carefree pirate ways, is now in a position related to the admirals. It creates a contrast. For example, in some fics, he has to enforce laws which is completely different from his normal 'break - the - rules - to - do - what - is - right' attitude.
The theme of acceptance is quite common. Fem Luffy often has to be accepted by the other characters in the story. This could be because she's different due to her gender or her slightly different personality traits. Also, the theme of self - discovery is prevalent. As fem Luffy navigates the pirate world, she discovers more about herself, her abilities, and her place in the grand scheme of things.
Nami could be a main character. She would be very worried about Luffy and try to find him. She might use her navigation skills to track down Law's ship. And she could be the one to try and negotiate with Law for Luffy's release.
Obviously, Luffy himself is the central character. But other characters like Nami often play important roles. In Smart Luffy fanfiction, Nami could be the one who helps Luffy understand complex concepts related to navigation or money management. Since Luffy is smart now, they might have more in - depth discussions about how to use their resources on the Grand Line.
There's a 'admiral luffy fanfic' called 'Luffy's Admiral Training'. In this fic, Luffy decides to take on some aspects of admiral - like discipline and strategic thinking - while still being his goofy self. It's an interesting take on how he could grow in different ways. Also, 'The Admiral Luffy: A Different Path' shows a world where Luffy becomes an admiral from the start and how it changes the One Piece universe.
Rayleigh would be a great candidate. He's an experienced pirate and has already trained Luffy for a while. He has a lot of knowledge about the world of pirates and could give Luffy a talk about the deeper secrets of the Grand Line or how to deal with the powerful enemies that lie ahead.