Kaido is planning something huge and we know what that thing is. War! But he’s not going to start just any war. He wants his war to be on such grandiose scale that it would be greater than that of Marineford or any war for that matter. He wants it to become the greatest war the world has ever seen.
But how does one start a war especially one of that magnitude? That would seem like an extremely difficult task to set up in the span of the next few arcs. That is, if it wasn’t being set up already. But before I discuss that let’s shift our attention to another thing that will happen before the war. The Reverie.
The Reverie… The meeting between the nobility of the World in which they discuss world issues. The people that will be there are:
Cobra and Vivi from Alabasta, Rebecca and Riku from Dressrosa, for the first time Neptune and Shirahoshi from Fishman Island, other world nobles, the marines, and guards for protection.
Potential issues they may be discussing could be the Warlord System, the downfall of Doflamingo and with Cobra there, perhaps the ancient weapons. All of those are theories I’ll save for another time, except the last one. The Ancient Weapons.
As stated before, Shirahoshi (the Ancient Weapon Poseidon) may be attending the Reverie in order to raise more trust between the Fishmen and the Humans. If it were to be found out that she is an Ancient Weapon, the World Government would capture her immediately try and use her her power.
What does Shirahoshi have to do with Kaido?
Well, my idea is the Reverie will end with Kaido capturing Shirahoshi, igniting the flames of war. The Fishmen are not going to stand (or swim) idly by as their Princess/ANCIENT WEAPON has been captured. They’re going to be furious and use all of their man power (or in this case Fishman power) and other aquatic animals to get her back.
How would Kaido know that Shirahoshi is an Ancient Weapon?
X Drake, who is working under Kaido, was on Fishman Island and captured Caribou. Because Caribou heard the private meeting between Robin and Neptune, he is one of the two humans (Robin obviously being the other one) that knows Shirahoshi is an Ancient Weapon. Caribou may have offered that information to X Drake to try and save his life or get released and X Drake could have relayed this information to Kaido.
While it is a good idea there is a problem with instigating only the Fishmen to start the Greatest War. The Fishmen would be severely lacking in man power against Kaido (especially on land) and that wouldn’t fulfill the role of being the Greatest War so there will be more people included. The Marines.
If Kaido successfully captures Shirahoshi during the Reverie, it will definitely gain the attention of the Marines. However, they probably will not have enough motivation to start a gigantic war with Kaido. So to ensure that the Marines and the World Government take him with absolute seriousness, He will announce to the World that he has an Ancient Weapon. This will not only throw the World into panic, but could gain the full attention of three potential groups involved in the war. First one being the Marines/World Government, the second being the Revolutionaries, and the third being the Worst Generation and their allies.
If the Revolutionaries find out about the Ancient Weapons, they will take action. They have spent years, possibly decades liberating Islands, gaining members, and gathering up weapons to take down the World Government. If they gained an Ancient Weapon, they could more easily take down the World Government.
The Worst Generation’s motives of being in the war vary depending on the person. Luffy and pals would be involved since half of the Straw Hats are close to, if not in Wano already (and Luffy’s the main character). Capone may potentially be there if he follows Luffy or is going after Kaido next. Law is already on his way to Wano. Kid could want his revenge against Kaido. Hawkins whereabouts are unknown but he may be under Kaido with Drake and Apoo. Blackbeard may go after him for a Road Poneglyph or the Ancient Weapon or both!
Anyway that’s about enough of my insanity/hype. Let’s Summarize my ideas.
• Kaido captures Shirahoshi during or after the Reverie to start the greatest war
• Fishmen get involved
• Worst generation gets involved
• Revolutionaries and World Government want the ancient weapon so they get involved
*Theory by Monkey D. Goku