Well, they might have a big celebration. Luffy would probably give Nami a huge, warm hug. Nami could show off her new skills or knowledge she gained in those two years. Maybe she has new maps or navigation techniques to share with Luffy. And Luffy would tell her all about his adventures and the new friends he made during the two years.
She could be a former pirate captain herself. Maybe she was one of the most feared pirates in her time, and her skills and reputation were passed down to Luffy in some way, even if he didn't know it was from his mother.
A potential storyline could be that they discover a new island together. On this island, there are ancient secrets that only Nami's intelligence and Luffy's bravery can uncover. This adventure could bring them closer as they face challenges side by side.
In this fanfiction, perhaps Luffy and Nami's relationship could deepen. Luffy might become more protective of Nami after two years of growth. They could go on adventures together where Luffy's strength and Nami's navigation skills complement each other even more. Maybe there would be some tender moments between them during quiet times on the ship, like sharing stories of their two - year - apart experiences.
Growth is a very common theme. Since Coby starts as a relatively weak character, many fanfictions focus on his journey to become stronger, both physically and mentally.
They could start with a big hug. Then Shanks might tease Luffy about his still - crazy appetite. Luffy, in turn, could show off his new crew members to Shanks.
In a fanfiction where Luffy meets Roger, it could be an amazing encounter. Roger might see in Luffy the same spirit of adventure and freedom that he had. He could pass on some hidden knowledge about the One Piece or give Luffy a cryptic hint about the true nature of the Grand Line. This meeting could also inspire Luffy even more, fueling his determination to become the Pirate King. It would be a moment full of emotion and significance for both characters and for the entire One Piece universe.
It could be a powerful pirate crew that has a vendetta against either Luffy or Sabo. Maybe they have some history with the Straw Hat Pirates or Sabo's group.
Well, in such a fanfiction, Luffy might gain some valuable advice from Roger. Maybe Roger could share his experiences about the One Piece and the Grand Line, which would inspire Luffy further in his journey to become the Pirate King.
A possible plotline could be a battle scenario. Maybe there's a powerful enemy threatening both Luffy's crew and Marco's group. So they meet on the battlefield and have to quickly figure out how to work together. Their different fighting styles, Luffy's Gum - Gum powers and Marco's phoenix - related abilities, make for an exciting combination in combat.