Exlor
Going for a prediction here. The Mech Kingdom is just an extension of the Metal scroll. The Metal scroll is far more all encompassing than Ves realizes, and Scrolls are almost like metaphysical laws governing humanity. The Metal Scroll has all sorts of pass or fail punishments and even though it facilitates advancement it also gives Ves incentives to advance himself and humanity.
here is my theory:The Kingdom of Mechs exist because of the uses of 3 scroll, Metal, Wood and Fire scrolls. it doesn't make sense that this contruct only created by the metal scroll, since the compact have both water and earth scrolls, they should be able to make their own versions if that's the case. there is a reason the wood scroll is never heard of again, my guess the wood scroll is eaten or sacrificed as the main ingredient. it is the main reason that enable normal human to evolve to become 'gods'. Wood is the element of life. the ancesion of human life from mortal to gods are their works. machine by itself can't help to evolve human. It's also the reason why the ingredients of life prolonged treatment are the brains of expert/ace pilots. their evolution of life are from the wood. while the metal scroll as the production machine and the processor or frameworks how the ascension work. then the fire scroll works as the energy to fuel this whole construction to work. it goes with our story about so far, the MTA and CFA only control the fire scroll while the wood scroll is totally gone or destroyed, while the metal scroll shattered in pieces and goes missing. also my theory is that Ves' mother is the Adept of the Wood lineage, not Metal. she somehow attain a piece of metal scroll during the whole conflict. so Ves actually from wood lineage, that's why his main actually life energy.