Well, the plot could involve Luffy being taken under Whitebeard's wing after an encounter. Whitebeard, seeing Luffy's potential, decides to train him. Luffy would then be exposed to the different fighting styles of the Whitebeard pirates. He'd probably have sparring matches with the stronger members, like Marco. This would make Luffy even stronger and more well - rounded in his abilities.
Well, in this fanfiction, perhaps the relationship between Luffy and Rayleigh is explored in more depth. We might see Rayleigh sharing his old tales of the Pirate King Gol D. Roger with Luffy. This could inspire Luffy even more in his journey to become the Pirate King. Also, Luffy's character growth in terms of leadership could be a great part. Under Rayleigh's guidance, he might learn how to better lead his crew and make more strategic decisions during battles.
Perhaps Dragon would also introduce Luffy to some new allies or inform him about the greater political and power struggles in the world of One Piece. This would give Luffy a broader perspective and help him understand the significance of his actions. He might learn about the true nature of the World Government and how to better fight against it, not just for the sake of his crew and friends, but for the freedom of the entire world.
One possible plot could be that Luffy, realizing he needs to become stronger in a different way, seeks out Mihawk. Mihawk, seeing potential in Luffy, decides to train him. Luffy would have to endure intense swordsmanship training, which is quite different from his usual combat style. This would also lead to some interesting character development as he struggles to adapt to Mihawk's strict training regime.
Luffy's character would likely become more mature. He'd learn discipline from Whitebeard's strict training regime. His view of the pirate world might expand as he gets insights from Whitebeard's long - standing experience.
Probably, the main plot is about Luffy's transformation under Rayleigh's training. Rayleigh could be teaching Luffy about the secrets of the Grand Line, the lost history, and advanced combat skills. Luffy then uses what he has learned to face new and more powerful enemies. For instance, he might encounter some strong pirates who are also after the One Piece, and he has to use his newly acquired skills to defeat them and protect his crew. The plot could also involve Luffy's crewmates waiting for him during his training and their own mini - adventures in the meantime.
Blackbeard could also be a main antagonist. He has his own ambitions for power and the One Piece. With Luffy getting stronger under Dragon's training, Blackbeard would view Luffy as a direct competitor. Their paths are bound to cross, and Blackbeard would not want Luffy to achieve his goals before he does.
The World Government could still be the main antagonists. Since Luffy is getting stronger under Mihawk's training, they would see him as an even greater threat. They might send their top agents, like the Cipher Pol units, to try and stop Luffy's progress.
A Saitama and Tatsumaki married fanfiction could have multiple plotlines. One could be that Tatsumaki, who is used to being in control, finds herself falling for Saitama's carefree and powerful self. Their courtship could be full of misunderstandings at first. Saitama, being oblivious as he often is, might not immediately pick up on Tatsumaki's feelings. Once they get married, they would face challenges like how to balance their hero duties with their new family life. Tatsumaki might want to keep their relationship a secret from some of the other heroes at first, while Saitama might be more open about it. There could also be a sub - plot about how they handle Tatsumaki's overprotective sister if she finds out about the marriage.
It could be really interesting. Saitama is extremely powerful in his own universe, and in a Dragon Ball Super fanfiction, he might be a wild card. Maybe he'd show up during a big tournament and shock all the Saiyans with his effortless strength. His simple, unassuming personality would contrast with the more flamboyant Dragon Ball characters.