Shortly after the Straw Hats’ arrival in Dressrosa, Luffy had tried to fly Momonosuke because of the flying ability that Momonosuke had displayed and used unconsciously to save both Luffy and himself from remaining in the pit wherein Luffy first stumbled upon him
, but Momonosuke dreadfully and loudly rejected the idea of flying ‘again’ through the ‘skies’ despite having no memory of the time when he had flown out of the pit together with Luffy, wherein there was no ‘sky’.
While he was about to shout his rejection of such idea, Momonosuke was recalling somebody’s hand reaching out to grab him.
That event from his memory appears to be the cause of his aviophobia(fear of flying). The person from his flashback is suggested to have a flying ability, and the Dragon Devil Fruit possesses a flying ability.
When Momo was loudly rejecting the idea of flying again, his father was composedly listening to what was happening with no sign of surprise. This indicates that his father is aware of the misfortune that befell Momo. This further suggests that this had happened long before both Momo’s consumption of an artificial Dragon Devil Fruit and their separate arrivals in PH.
At Punk Hazard, Kinemon both exhibited great abhorrence of ‘dragons’ and confirmed to Brook that he has a ‘personal vendetta’ against them. I do not think that such hatred and vendetta could develop from having his ‘lower third’ attached to a dragon (the first dragon that greeted Luffy, Zoro, Usopp and Robin when they first set foot on the blazing half of Punk Hazard) since it is normally IMPOSSIBLE for one to confirm by only his lower third the nature of the being or thing to which it (his lower third) was attached.
Kinemon also showed great detestation of ‘pirates’ when sanji had first introduced himself and the rest of his group to him as pirates.
After Momo had consumed Vegapunk’s artificial Dragon Devil Fruit and successfully managed to escape his pursuers at Punk Hazard, he found himself facing a mirror. Upon looking at the reflection of his dragon form on the mirror, he paled and shouted a loud scream. This appears to be a phobic reaction to dragons.
When Luffy and Momo were stranded in that pit, Luffy introduced himself to Momo as the man who will become the pirate king. Upon hearing that, Momo had become fidgety and nervous and gave a description of ‘pirates’ that matches Kaido’s description. This could suggest that Momo met Kaido in person, and his nervousness could be due to the fear he harbours about Kaido due to a certain event/ events.
When Kaido’s underling was trying to update kaido with the news of Joker’s defeat, he was looking toward the sky, which means that he believed that Kaido was in the sky, if not on the apex of some mountain.
In that very chapter, Kaido reached sky island with neither the company nor the knowledge of his crew members.
It was shown to us that Drake and several other crew members of Kaido were talking about the news whereas Kaido himself was on the sky island.
It was therefore evident that such method of attaining sky island is strictly related to his abilities.
In this week’s chapter it was revealed to us, along with his identity, that Kaido has the strongest body structure you could find in all the living things that swim, crawl and fly this earth. Dragons are known to possess such attributes as robust scales that could withstand blades and spears that aim to penetrate their skin as well as wings that allow them to fly and reach such altitudes. Since Kaido’s body was described to be immune to blades and spears that aimed to penetrate it, from this aspect his attributes strongly support the idea that he possesses the Dragon Devil Fruit.
After Caesar’s downfall at Luffy’s hands, Kinemon told his son, in the middle of their meal, to trust that ‘they’ are all right.
My theory is that ‘they’ refers to the people from Wa. To be worried about their safety means that they are going through some kind of crisis. A crisis of this level that affects an entire nation whose citizens are so strong inasmuch as not even the marines can go near them can only be caused by one of the four emperors.
When the Straw Hats, Law and the samurai had left Punk Hazard and were heading to Dressrosa, Law revealed Kaido’s epithet. Upon hearing that, Momo and Kinemon both showed expressions fear and shock. When asked by Zoro what was wrong, Kinemon untruthfully replied that nothing was wrong.
Right after Kinemon had untruthfully answered Zoro that nothing was wrong, he reacted frightfully to the dragon form of his own child and started nervously asking about his (Momo’s) whereabouts. Kinemon’s mind should have been preoccupied by the dragon next to him, but the very sight of that dragon triggered feelings of worry about his son’s whereabouts.
Afterwards, when everyone was gathered and having dinner, Kinemon revealed to them that they were ‘chased’ by people whose identity he wished not to reveal(probably for the safety of the people who aided him recover both his body portions and his son – the Straw Hats).
In both instances Kinemon concealed matters connected to kaido. In this week’s chapter we discover that Kaido’s goons were ‘chasing’ the ‘samurai’.
This establishes another strong connection between Kaido and the people of Wa. My theory is that Kinemon’s group was chased by Kaido’s goons when they were trying to go to Zo. And the crisis that befell Wa had been caused by Kaido.
Kaido is the only one that could have breached the strong security of Wa and did what was done to Momo by his flying abilities. This explains Momo’s accurate description of Kaido, his phobic reaction to dragons, and the fear he harbours about him from the event that caused him aviophobia. This also explains Kinemon’s ‘personal vendetta’ against ‘dragons’, his feelings of worry about the whereabouts of his child that surfaced at the sight of a dragon, and his strong dislike of ‘pirates’ because it is only natural for one to develop such feelings after having his son exposed to such traumatic experience and his country exposed to such crisis (conquest of Wa).
Let’s also not dismiss that Gear 4 was conceived to combat celestial/ flying enemies too.
These are my thoughts for why Kaido must possess the dragon ability.
Thank you for reading.
*Theory by Australopithecus