So there’s been a lot of ideas thrown around of who else could potentially get involved in order to make Wano surpass the Marineford events.
First, let’s review the big events that transpired in Marineford:
Marineford was mainly 1 Yonko (Whitebeard) vs. the full force of the Marines. Another Yonko (Kaido) almost got involved, a 3rd Yonko (Shanks) stopped that from happening and forced the war to conclude. This resulted in the death of a Yonko followed by the rise of a new Yonko (Blackbeard).
So far, Wano’s conflict is against 2 Yonkos who have teamed up.
This time, the Marines are the ones to potentially get involved farther (SWORD, CP0, Kizaru).
At the same time, two other Yonkos are making their own unknown moves (Shanks met the Gorosei not sure what he’ll do next, Blackbeard going ahead with a move after reading the aftermath of Reverie).
So how can the current things we have be used narratively to make Wano into a much more explosive war that dwarfs the events of Marineford? Here’s a few things ways:
1- While two Yonkos are already involved, Blackbeard has more than enough reason to get his hands involved. We have known since the time skip that Blackbeard has been seeking out powerful devil fruits and what better place to find strong Zoans than the casualties of the war in Wano? But Wano seems way too risky for the calculated Blackbeard to get involved in. That’s where his two latest allies come in: Aokiji/Kuzan and Moria.
Think about it. Blackbeard could have easily just taken Moriah’s fruit, but Moriah could prove himself useful by going to Wano and get devil fruits in exchange for his life (plus Moriah has a motive to make a move against Kaido). On the other hand, Aokiji is someone Blackbeard doesn’t seem to fully trust yet. Maybe he can use this opportunity to prove his loyalty to… get the Poneglyph rubbing?
Aokiji is currently one of Blackbeard’s strongest allies so he’s more than capable to fending for himself in a dangerous place like Wano and his willingness to go to such a place is proof of his loyalty. But wait there’s more. Marineford had one betrayal with Squardo, but Wano has had so much more betrayals already and I think Aokiji officially being confirmed as a member of SWORD (inspired to infiltrate Blackbeard by Drake’s success) will be the climax of these betrayal reveals.
2- How much will the Marines get involved? Well with Drake outed as a member of Sword and CP0 having a presence in Wano and Aokiji potentially coming as a member of SWORD (maybe he’s sent by Garp) there are a lot of possibilities.
However, I think the official Marine involvement will be the aftermath where Kizaru shows up to put an end to the war by either arresting the losers of the war or he might even be the one to finish off Kaido or maybe that’s what Big News Morgan will say to make the Government look better and stronger than ever.
This news could be the headliner along with the announcement of which Shichibukai have been arrested with the new weapons. Maybe Kizaru will focus on the arresting the Big Mom Pirates while Big Mom herself chases the Straw Hats to Elbaf and Aokiji/Moriah also escape leaving Kaido and the Big Mom Pirates to fend for themselves.
3- What are Shanks and Blackbeard doing?
Well with news after the Reverie involving Alabasta, I think Blackbeard could make a move for Alabasta with his actual crew in order to claim the Poneglyph or even find Pluton itself. In contrast, after failing to get the support of the Gorosei to stop Blackbeard, Shanks has two options: 1. Go stop Blackbeard himself 2. Be controversial again and bet on the new generation by declaring himself as Luffy’s ally in full faith that Luffy will succeed in taking down Kaido (of course this is after he meets Bartolomeo who hypes Luffy up enough to inspire Shanks).
Of course Shanks could still stop Blackbeard himself and face casualties, but I believe Shanks can choose not to do that if he trusts in Luffy and instead focus on being Luffy’s finalt test before facing Blackbeard.
So if all these things happen, I think the the entire One Piece world will forget Marineford because of how worldshaking the aftermath would be. At least one Yonko dead (Kaido), 2 Yonkos rising in power (Luffy and Blackbeard), another Yonko (Big Mom) in crisis, and the final Yonko willing revoking his rights as one to be allied under another. Meanwhile the Marines look stronger than ever after taking down most if not all the Shichibukai and allegedly Kaido. That would be a whole level of insane from any witnessing side (all sides would have reactions to what the other sides accomplished during the Wano conflict).
*Theory by a_foolish_heart