"One Piece" Chapter 816 truly became a major shocker as it was revealed that the Minks are lying about Raizou being on Zou island and that they protecting him; in Chapter 817, fans are anticipating to finally get a glimpse of Raizou and expect a major development in Luffy and the Strawhat pirates' quest in rescuing Sanji.
In a "One Piece" prediction published in Oro Jackson, slazer77 said that Chapter will show how Inuarashi and Nekomamushi will explain to Luffy and the Strawhats how the relationship of the Minks and the samurai of Wano developed. Inuarashi and Nekomamushi reveal that back in time, the samurai fought against the World Government to protect the Minks. This happened during and after the so-called Void Century when the Minks were being sold off as slaves.
Kanjuro, Kin'emon and Momonosuke, the theory added, were overjoyed to have heard about Raizou. When they asked about the whereabouts of Raizou, it will be revealed that Raizou has been hidden in the belly of Zunisha, which would shock Luffy and the Strawhats. Zunisha is an enormous elephant that carries the island of Zou on its back while wandering the New World.
Further to the story, Law will urge Luffy and the Strawhats to leave Zou in fears that Kaido will be coming back and would destroy the place again. It also reminded Luffy of their mission to rescue Sanji. Kin'emon informed the crew that Kaido is currently in Wano and have taken over the place.
Law suggests to the group to split up. And to the delight of Luffy, Inuarashi and Nekomamushi step in to help the Strawhats in repayment of their deeds for saving Zou.
A separate theory by shaunak0304 said that in Chapter 817, fans will be finally introduced to Raizou, who upon gaining consciousness throws a sharp object towards Luffy but will be quickly dodged by Luffy. Raizou, accordingly, apologizes to Luffy as it was,according to him, only his "ninja instinct."