The King of the Fish-Man Island! Neptune, the God of the Sea!

The King of the Fish-Man Island! Neptune, the God of the Sea!

Available on Prime Video, Netflix, Crunchyroll
S15 E14: After reuniting with Nami, Luffy and the gang are invited to the royal palace of Neptune, god of the sea; the New Fish-Man Pirates exploit the power of a designer steroid in order to terrorize humans.