During the Fishman Island arc we learn the story of Vander Decken the man who sailed to Fishman Island went crazy. In the tale it was said that "He went Crazy and killed his own crew" does that not sound similar to Rox after Domi Reversi?
What if Imu somehow found out about Poseidon and the Mermaid Princess and tried to control Vander Decken to get it?
What if Imu somehow found out about Poseidon and the Mermaid Princess and tried to control Vander Decken to get it?