@Watch-man:
So 4 more volumes? Not gonna happen, two more volumes(so 2 and a half from now) are max what I expect. Flashback could last like two chapters and we are left with 15-20 chapters. Plenty of space to cover tons and tons of stuff. How do you see 40 chapters more? I mean like really how??
Its hard to explain but I don't think this arc is going to go down how many expect. Emperor alliance is beaten, celebrate the victory, leave Wano. Which could take indeed about 20 chapters.
But I expect that Luffy will still struggle against Kaido, maybe he "beats" him in a 1v1 but Kaido comes back, like Luffy did before him, that's where I assume Kaidos flashback come into the story. As I imagine the flashback, we might get some more backstory for Kaido and Big Mom, even possible some information on why Kaido choose Wano as is headquarters besides its geography and of course Rocks.
Then Momos plot line will either be resolved when Kaido is down for good, or when he is beaten in his first round. Maybe he joins the fight with Yamato, Marco, so we might get the complete victory over Kaido with the Momotaro legend, with a 4v1, or 6v2 if BigMom should join Kaido with Kid and Law. Also the 9 shadows of Tokis prophecy might come back into play.
There are to many options left in my head.
All that is not set in stone, as it can change with the coming chapters, but with the current progression of the story I assume that we have about 4 Volumes left for Wano.
Volume 105/106 seems like a fitting timeline IMO, but as I said nothing is set in stone, as of now.