We all know from the beginning that there’s going to be a big clash with Kaido on Wano, and after that we’ll have the series’ endgame which will be a war that encompasses the entire One Piece world.
However, I think that instead of the clash on Wano and the final war being two isolated storylines, one will bleed into the other and Wano will end with war consuming the One Piece world.
Think about it, in Kaido’s introduction, the big take-away is that he wants to start the greatest war the world has ever seen. The problem is that if you assume the war Kaido wants to start is strictly limited to the clash on Wano, than his statement is false because we know that the war that follows Wano will be even greater. Furthermore, since Kaido is setup to go down in Wano, he won’t even be present in the final war anyway. However, if you instead assume that the clash with Kaido is the trigger for the all-encompassing war, than Kaido’s statement makes much more sense.
It would be similar to how Oda handled Blackbeard and Doflamingo’s respective speeches. In Impel Down, Blackbeard promised us something that would shake the very foundation of the One Piece world, and he accomplished this. By killing Whitebeard and being the first person to consume two devil fruits, Blackbeard truly did shake the foundations of the world. Doflamingo on the other hand spent the entire series preaching about the coming new era, how excited he was to be a part of it, and how everyone was making moves towards it, but the ultimate irony is that it was his defeat that triggered the throne wars for the new era.
Kaido would fall into the same category – he claims that he wants to start the greatest war the world has ever seen, and he will! It’s just that his defeat is what will trigger it. And the fact is that Wano has the perfect setup to bring everyone into such a global conflict.
The alliance between Kaido and Big Mom changes everything. Remember how the World Government and the Marines were extremely paranoid that Shanks and Whitebeard would ally? They sent blockades and intercepting ships to prevent those two from meeting. Their biggest fear at the time was an alliance between Yonkos because they didn’t have the forces necessary to combat that. Just like we saw at Marineford, the combination of the Marines and the Warlords is only strong enough to deal with 1 Yonko fleet, not multiple.
The Yonko alliance is literally the worst case scenario for them. Now that Big Mom and Kaido are allied, the Government has to act, or else they risk losing the stability of the entire world. Thing is, now they have the means to do something about it. If Vegapunk’s weapon is strong enough to completely obsolete the Warlord system like Fujitora claims, than the Government would want to put that to the test. Hell, they’d want to make an example just like they did with Ohara. Imagine how beneficial it would be for the Government to be able to say “we have enough military might to squash even a Yonko alliance”. No one would want to mess with them. The Yonko alliance pretty much guarantees that the marines will get involved, especially now that the Reverie is over and they utilize their resources elsewhere. Furthermore, because their attack plan would involve Vegapunk’s weapon, he’ll need to tag along to oversee its usage.
Yes, Vegapunk will also make an appearance this arc. Back in chapter 929, Oda gave us scene between CP0 and Orochi where the latter demanded that the former bring him Vegapunk, or else the government won’t have access to Kaido’s weapon supply. Everyone thought at the time that it was ludicrous that the Government would agree, but how about now? Fact is that Oda would never have included this scene, especially in Wano where every page matters, if there was no purpose to it. The Government rejecting Orochi’s proposal does nothing to advance the story. I find it far more likely that the government agrees to Orochi’s proposal, in which case the question then becomes why would the Government sent Vegapunk to Wano.
Vegapunk unleashing his weapon to subdue the alliance and show the world the Government isn’t to be trifled with would be perfect cover for sending him. All CP0 has to do is agree to Orochi’s demands, allowing a ship carrying Vegapunk to sail through the waterfall into Mogura port and enter Wano proper, only for the government to then betray their deal and unleash Vegapunk’s new weapon on the Yonko alliance.
I can’t understate how much Vegapunk’s presence is needed this arc. There are so many unanswered questions in Wano that only he can resolve. Why are Ceasar’s fruits incomplete? How do they differentiate from actual Devil Fruits? Why was Momonosuke’s artificial fruit considered a failure? How will the citizens of Ebisu town be cured of the SMILE side-effects? Questions like these are only relevant in Wano and it would be bad writing to resolve them in a later arc. As such, Vegapunk needs to show up now to answer these questions.
A global war can’t be complete without the Revolutionaries, and they too have a dangling plotline that will lead them to Wano. The only reason Sabo, Koala, and Hack infiltrated Dressrosa was to figure out where Doflamingo was obtaining the weapons he was shipping. Instead, all they found was something called Drunken Iron Ore, a mineral that according to Koala only some countries produce. But, now that we’re in the midst of Wano, we know that Kaido was producing these weapons out of Udon; the same weapons that Orochi is offering to exchange for Vegapunk. We don’t know what everyone mining in Udon, but is it such a stretch to think that it’s Drunken Iron Ore? A mineral that Kaido, a drunk, uses to build his weapons? Come on. All this being said, why would the Revolutionaries not infiltrate Wano, especially now that the Government has shown interest in the very weapons the Revolutionaries tried to find in Dressrosa?
Just like that, both generations of pirates, the Marines, the World Government, and the Revolutionaries become at war with one another. This is how the world of One Piece descends into the greatest war it has ever seen, with Kaido as its ultimate catalyst just like he promised back in his introduction. But just like Doflamingo, the irony is that Kaido, the World’s Strongest Creature, will be its first casualty. This setup would allow the conflict on Wano to resolve while keeping tensions at an all time high. It also explains why the Reverie needed to happen alongside the start of Wano. Lastly, considering Oda needs to have the One Piece world fall into conflict for the endgame of One Piece to make sense anyway, this saves him the trouble of introducing new plotlines in order to make it happen, instead having it happen naturally with the story beats he’s already setup.
*Theory by Therrester