Their relationship might become more of an equal partnership in terms of strategizing. Usually, Luffy is more about action, but a smart Luffy could contribute intellectually to Robin's plans, making their bond stronger as they rely on each other's skills more evenly.
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.
It's popular because it shows a different side of their relationship. People like to see Luffy being more than just his usual carefree self and using his smarts in relation to Nami. It adds depth to their dynamic.
I'm not sure of a specific 'luffy is actually smart fanfiction' to recommend off the top of my head. You could try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net.
Another idea is that in the fanfiction, Luffy's intelligence is related to his ability to understand ancient languages or prophecies. This could lead him on a new adventure to uncover hidden secrets in the One Piece world, like the true meaning behind the poneglyphs. He could then use this knowledge to get closer to the One Piece.
One interesting Smart Luffy fanfiction could be where Luffy uses his new - found intelligence to outwit powerful enemies in a strategic way. For example, instead of just charging into battle, he devises elaborate plans that take into account the enemy's weaknesses.
One idea could be Luffy using his intelligence to outwit powerful enemies. For example, instead of just relying on his strength in a fight against a devil fruit user with tricky abilities, he figures out their weakness through careful observation and then uses it to his advantage. He might also use his smartness to form strategic alliances with other crews or kingdoms in the One Piece world.
It could be a super intelligent pirate who has been secretly controlling events in the One Piece world. This antagonist might be several steps ahead of everyone, creating elaborate plans to take over the Grand Line. Luffy, with his newfound intelligence, has to match wits with this foe.
First, you need to define how Luffy becomes smart. Is it through a special event, like eating a new type of Devil Fruit? Or maybe he gets a sudden inspiration. Then, think about how this new intelligence will change his relationships with his crewmates. For example, will he start giving more strategic advice to Nami during their adventures.