During the Levely arc we discovered that Kaido and Big Mom have been affiliated with each other in the past, as Kaido seems to owe her a huge debt, that she said lasts for a lifetime.
According to Garp, their connection with one another stems back to over 40 years ago.
As we have seen in chapter 934, Big Mom and Kaido are revealed to be former comrades.
So if Big Mom and Kaido were working with one another that long ago, it is possible that they may have had an actual “relationship” with one another. The main point I’m getting at here is that I believe some of the children in Big Mom’s crew are Kaido’s kids. More specifically Katakuri, Daifuku, and Oven. Katakuri, Daifuku, and Oven are all 48 years of age which is definitely more than 40 years ago. In addition to this, the resemblance between Oven and Kaido is uncanny. Their facial structure as well as their beards look almost identical when put side by side. They just look like father and son.
Yes, Katakuri and Daifuku don’t look as much like him, but they are triplets after all. Kaido as their father would just make sense based on how ridiculously strong the three are. Exactly what you would expect of the children of two Emperors.
In chapter 954, Kaido and Big Mom reveal that they have formed an alliance to take over the world and they plan to resume their fight afterwards.
Before the announcement, Big Mom mentioned something about an anniversary which will be on the Wano kingdom’s Fire Festival, the same day Straw Hats alliance planned to retake the country from Kaido’s tyranny.
Well, but anniversary of what? The end of the Rocks Pirates? An old marriage between Kaido and Big Mom?
Or Kaido’s possible sons with Big Mom?
*Theory by TallysTown