Let me ask you. What do you think the point was of Oda building a bond between Zoro and Hiyori earlier on in the arc? Normally Oda builds the bond between Luffy and the Princess of the Arc. And yes, Hiyori is a Princess, as her family ruled Wano. This is the one and only arc where Luffy has nothing to do with the Princess, and that role was distinctly given to Zoro. Hiyori's story however, has practically nothing to do with Kaido, and everything to do with Orochi. Luffy has nothing to do with Hiyori or Orochi. Zoro on the other hand..... If one properly follows the story and the narrative that's being driven, there is only one path on Zoro's course that will complete the narrative established for his character in the early stages of the arc. Oda completely ignoring those plot threads he established, for Zoro to randomly pop up and kill Kaido, is terrible from a writing perspective, and throws all those preestablished plot threads out of the window, and basically renders them pointless to have been written in the first place. But a lot of people around here don't read One Piece from a proper narrative standpoint, so bring on ZKK!