Kaido’s Ace
Madame Shyarly saw a prophecy that a human with a straw hat would destroy Fishman Island. Naturally she assumed it was Luffy and the popular fan theory is that he will do this by destroying the Red Line. And that he is the one who will fulfill Joy Boy’s promise in his place. Since the person is in silhouette I theorize that it is a different character, I think it was foreshadowed with the Fake Straw Hat Crew.
I believe it will be “One” from the Numbers. Since the Beasts Pirates have a card game motif “One” will be the Ace of the Beasts Pirates meaning it’s strongest member. I believe he will be humanoid like Hatcha since Shyarly saw a human in her vision.
I believe the straw hat Shyarly really saw was the giant one hidden in Mary Geoise. Which I believe “One” will retrieve on his way to Fishman Island.
So if Luffy is not the person Madam Shyarly saw in her vision why did he trigger her vision? She states that she saw something calamitous in Luffy which is why she looked into the crystal ball. I think Luffy will be the indirect cause of Fishman Island’s destruction, Luffy essentially freed Caribou.
Who knows the truth that Shirahoshi is Poseidon, he even stated he wanted to pass along the information to a certain someone to curry favor with them He is the second Chekhov’s gun from the FI Arc right behind the Tamate Box. I believe “One” will somehow get the information from Caribou and he will go to Fishman Island for Shirahoshi. Neptune stated if the secret got out powerful forces would come after her government and pirate alike.
If my theory wasn’t tinfoily already I think “One” will look almost identical Crocodile. I have two main reasons for thinking so.
I believe Caribou will leak the truth about Shirahoshi to “One”. Interestingly in his mini arc it was revealed he greatly resembles Gaburu, which could be precedent/foreshadowing for the reveal of “One”. He will probably lack the scar and have both hands.
And two The Numbers are reminiscent of how Crocodile set up the Agent system of Baroque Works were all male agents had numbers for code names. He was revealed to be Mr. 0 the leader of this organization and he did have close relationship with Daz Bones Mr. 1. Over all Wano Arc is similar to the Arabasta arc, the New Onigashima Project is similar to Operation Utopia both wanting to to take over a nation and turn into a pirate paradise.
Crocodile has a secret weakness that Ivankov knows about. I think the most popular theory is that Crocodile was a woman. Maybe after turning into a man Crocodile now resemble “One”. Whatever it is it seems tied to his appearance. In the Strong World chapter we don’t see his face.
Or it could just be he coincidentally looked like Crocodile (similar to Tashigi with Kuina and Caribou with Gaburu) and he got captured by the Marines after being mistaken for him later being included in Vegapunk’s gigantification experiment. Which reminds me of Duval who got mistaken for Sanji without the benefit of facial reconstruction.
