My theory is that crazy scientist Vegapunk is a descendent of the moon people’s from Enels cover page and is a descendent of the moon people who settled on the sky island of Birka.
In the cover story there were autonoma, a mechanical race possibly left over from the moon society who descended to the one piece world many years before the story began and became the skypians, Birkans, and shandians. The autonoma race was also shown on the island franky was sent to during the 2 year time skip which is also where vegapunk was from. So maybe somehow vegapunk ended up on that island when he was young or some birkans continued onto the blue sea and created a settlement there. Vegapunk being a genius probably made the autonoma on that island because he was studying his past or something.
We know by the development of the history. That vegapunk is a scientist that has developed many technologies, and we know that he applies all his knowledge into the devil fruit (AkumanoMi) research. By this we know as a fact that people point out that Vegapunk accomplishments are the follow (maybe I am forgetting some, help me with this one on the comments):
Creating and installing on the pacifistas, the kizarus Laser.
The Creation of a pair of Dragon Clones in punk hazard and bringing them to life.
The Creation of a Synthetic Devil Fruit. (The first One was the Zoan Sintetic model Dragon)
The creation of kairouseki.
And by this facts my theory is one in wich Vegapunk knows how to extract the essence of the Akuma no mi, kinda like his pure Form, like an aether. In the case of the akuma no mi known as the pikapikanomi his essence was made into laser weapons. In the case of the Vegapunk’s man-made Zoan-type Devil Fruit by applying his studies of this aether to the sintétic fruit, the Pair of Dragons guarding PunkHazard were made from this essence, making stringer the theory. And the last one is the kairouseki stone, he somehow knows how to extract the energy from even the sea, not only from his acursed Akuma no Child’s.
Fujitora said that he had met up with Vegapunk and that he had invented something strong enough to replace the seven warlords. We know that he is capable of producing Lazer shooting cyborgs and Dragons. Why not combine both into Lazer shooting cyborg Dragons? it shouldnt be a problem. now add the possibility that he created a more refined method of creating giants after taking a look at the kids rescued from Punkhazard and we have pure awsomeness.
I am not done yet. Remeber that Vegapunk has ties with the revolutionary army. there has to be a reason why Kuma decided to become the first pacifista. we also know that you can implant commands in the brains of the cyborgs. Kuma was forced to protect the starhats ship during the time skip. And isnt it a big coincidence that the RA decides to declare war on the Celestial Dragons, just when Vegapunk creates a new invention?
This is what I guess will happen: Vegapunk produces Giant Lazer shooting cyborg Dragons, every single one with a command implanted to support the RA by any means.. After the RA’s declaration of war the marines will put more and more rescources in te production process