we all remember when Madam Shyarly said that luffy will destroy Fishman Island ... we dont know how or when
all i know that is madam shyarly prediction is 200% right and she predicted the Great Age of Pirates as well as Whitebeard's death
The key is Caribou and Shirahoshi ( Ancient Weapon - Poseidon )
Caribou got caught by Kaido recently somehow he will tell him about Shirahoshi Ability
we know that Kaido will do anything to Powerup his Army like we've seen
in smile deal with Doflamingo ( Gifters )
then Kaido will go to steal it from Fishmand island
and luffy will hear from someone ( Jinbei maybe ) the situation
luffy will try to follow Kaido and stop him
