Many people speculate that Blackbeard will invade Whole Cake Island to get the Road Poneglyph and probably fight Katakuri in the process. It’s a good theory, it makes sense but that’s not how I think things will turn out.
So, you know that Big Mom and Kaido just formed an Alliance. Now that Big Mom has free access to Wano Country, I can see her calling Whole Cake Island to tell the news and bring some more forces (maybe that’s how the Marines will find out about this alliance).
I really can’t imagine this HUGE war without characters like Katakuri, Cracker, Jinbe and some others. And we know that Poneglyphs, even though they’re pretty heavy, they can be carried (Jinbe found one and brought it to Big Mom), so what if, the rest of Big Mom Pirates come to Wano WITH the Road Poneglyph?
This would be PERFECT for Blackbeard. During this war, there will be literally 3 of the 4 Road Poneglyphs in one place! All he has to do is go to Onigashima, wait until everyone is fighting, use the powers of Shiliew and Catarina Devon to get the Poneglyphs, sit down a little, and after the fight is over, steal Kaido’s Dragon Zoan Devil Fruit.
Well, that’s how I think things will turn out. What do you guys think?
*Theory by Pirate_Indigo98