This will be a really short theory compared to my previous ones, as it is highly speculative (and quite crazy). I just wanted to get it out there for now. I will possibly revisit it in the future if supporting facts are introduced.
Okay, so, the cornerstone of this theory is Vegapunk. He has been shown to be a genius scientist who has knowledge on the fields of each of his past assistants / co-researchers, at least. Namely, Caesar's SAD application was based on Vegapunk's research, Judge's cloning technique was based on the research he once conducted with Vegapunk on the lineage factor and Vegapunk has been shown to be an engineer just as skilled, if not more, as Queen in light of innovations such as the blueprints Franky used to make general Franky and the Pacifista project.
However, compared to them, we still haven't seen where the accumulation of Vegapunk's knowledge and research has led to...yet. What if Vegapunk's "masterpiece" is a product of combining his knowledge, research and skills in all the aforementioned fields? (possibly not Caesar's)
What if Vegapunk has managed to find a way to mass produce enhanced humans like Reiju, Sanji and all the siblings? With the difference being that Vegapunk's method could be used straight away on fully grown men or even clones. On top of being enhanced, they would technically not be humans if Vegapunk also applied the research from the Pacifista project to also make them cyborgs. And on top of making them cyborgs, Vgapunk could have also created blueprints for a mass produced model of armor similar to the Germa's raid suit.
This last part is quite interesting. We know Vegapunk has at least thought of building something akin to a raid suit before as he created the blueprints for general Franky. It's not quite the same but the idea of using a shape-memory alloy to build a suit existed since then. But it was not possible back then due to the lack of such an alloy. But what about now? Now there's the wapometal, a shape-memory alloy made by Wapol. Interestingly so, the world government / tenruibito are the ones who sanctioned Wapol and made him the king of an entire kingdom (Black Sakura Kingdom). That could have very well been thanks to a deal for Wapol to provide them with a constant supply of the shape-memory allow that is wapometal.
In other words, Vegapunk may have managed to find a method to mass produce SBS (Super Cyborg Soldiers), which I guess would be the equivalent of mass producing the result of a fusion between Captain America and Iron Man's suit. Theoretically, Vegapunk may also have completed his artificial devil fruit research and even add artificial devil fruits to the mix but the SBS is already overpowered enough as it is so let's not push it.
I hope you guys enjoyed it, feel free to let me know what you think about the theory or your own speculations on the world government's new weapon.
This was a theory made by yours truly, Yuuzume. :