In Chapter 1035 King reminisces about him joining Kaido. They met at the Third Research Institute on Punk Hazard, where King was experimented on until being released by Kaido.
The parallel drawn between Kaido/Alber and Luffy/Zoro is pretty clear.
Kaido’s drastic change of personality was of particular interest to me. Throughout the story there has been a recurring theme of smiling, joy and laughter. These are clearly very important to the story, symbolically. Seeing Kaido go from a man sort-of like Luffy, in terms of his demeanor (constantly smiling), to the cruel, alcoholic, occasionally suicidal Kaido of present day makes one very eager to learn just what it was that caused this drastic change in him. To see a crew that started out so similarly to the way the Straw Hats did become a source of so much cruelty and suffering is pretty tragic.
The bond between King and Kaido highlights how much better Kaido is at taking care of a little brother than his own child.
King, on the other hand, holds immense trust and fealty to Kaido. They formed the Beasts Pirates together with a shared goal of changing the world. As to why they want to isn’t clear for now, but King’s potential resentment towards the world for what they’ve done to him, and the fact he is the last remaining Lunarian, may be what motivates him to follow Kaido’s vision, which is a world of violence.
Chapter 1035 basically confirmed where King and Kaido were experimented on. It was none other than Punk Hazard.
Someone pointed out that the burning background panel with the two side by side is none other than the Third Lab of Punk Hazard which is also where most of the Punk Hazard arc took place and where we first met Caesar. Biggest giveaway is the PH-006 on the right building. And this is the same lab over 3 decades later after Aokiji froze the half where the Third Lab is. The PH-006 is still there as well at the right side of the panel.
Big Mom gave Kaido his Devil Fruit while they were part of the Rocks Pirates. Kaido looks very young in the flashback. He is currently 59, and the Rocks Pirates were defeated in God’s Valley 38 years before the current time in the story, which means he was 21. So what probably happened is the Marines captured Kaido after they defeated the Rocks Pirates in God Valley because he is an Oni and they wanted to experiment on him. Kaido was probably a prisoner only for a short while, long enough for Vegapunk to copy his Devil Fruit, but short enough that he still looks like he’s in his early 20’s. Probably anywhere from 3 months to 3 years. We know this is where he met King, he most probably took the Numbers at that time too.
Really makes me wonder how Kaido went from wanting to flip the world upside down to wanting to kill himself. Also, how did he go from someone who was experimented on by Vegapunk, to someone who would make one of his closest collaborators his 2nd mate (Queen) and do business with Ceasar, another man related to Vegapunk?
