So I went back to read the chapter where Zoro defeats Kamazo and something in my brain sorta clicked.
Before I get into the actual quote, I will lay out some facts that support my theory.
He has immortal like qualities, and he’s referred to as a “thing” by Big Mom;
He has been defeated many times as a pirate;
He has a dragon form;
He rules Wano from the shadows.
So, we don’t know anything about Kaido’s past but we DO know he can’t kill himself. It is totally possible that Kaido has been alive for a very long time. Maybe he was even alive when Ryuma was in Wano. Look at this panel.
Do you think Oda ever mentions stuff like this for no reason? I feel like this is a classic Oda twist that is right under our noses. Kaido’s scar must have been from something huge right?
Now imagine that Gekko Moria KNEW about this information. It would make total sense for him to try and bring Ryuma back from the dead to get revenge on Kaido, as we saw in Thriller Bark. What do you think?
*Theory by KingOfThePilots