I really want to know how Valk units are made.
I talked a bit about this back when the thread started but might as well list it out, here's some truncated notes, I have this as a timeline but eh, focus it down.
Immediately Post Impact humanity is suffering pretty much as you would expect, global commerce extinct, CONUS, North West Africa and EU nations directly hit by the major fragments of the Impactor and smaller meteorites raining down pretty much globally, tsunamis for all Pacific and Atlantic coastlines, global firestorms, global super storms, acid rain which was thankfully not global, USA and Russia Deadhand systems launching their WMD stocks thankfully most knocked off course by inclement weather, the whole nine yards. The methane release from frozen stocks being disrupted countered the nuclear winter effect so yay I guess?
Now amongst all the wreckage there would be these tiny white globes could occasionally be found.
Naturally, people started hitting them with hammers to see if they would break. No one hit quite hard enough to the relief of historians currently.
But occasionally, with direct skin contact, they would apparently just disappear into humans body, which would naturally freak them out and have them say "do not want"which would cause it to reappear.
Pretty useless really, if apparently completely harmless so lab conditions got relaxed and then one researcher wore a digital wristwatch whilst handling those 'weird snowglobes' and then suddenly realised that she knew the exact geographical time of wherever she was standing through a heads up display. Her wrist watch was also missing and when she wanted it back it appeared in her hand and she no longer knew the time. Wow, you get a forcefield? Awesome how come we never noticed this before?
Science occurs.
It's discovered that these miracle machines could pretty much absorb, repair and improve upon any technology given to them. So naturally one person asked if she could absorb a defunct solar electrical power grid. She could. Suddenly amenities. Food processing plant? Yep, then spit it back out and it's brand new. Chemical processing plant? Yep, what do you need, I can synthesise basically any industrial chemical. Heavy metal working plant? Yep, feels slower taking this in than before though... Sewage processing? Oh god no what please don't make me... fine. Yes it works. No I'm not going to let you pump sewage into a machine I'm attached to that's fucking gross let me spit it back out.
It's discovered that synched machines can either be stored 'somewhere I dunno' or completely external so long as they stay within range of that weird forcefield.
Suffice to say, more science occurs, other people are discovered to be compatible with the god machines and the start of proper rebuilding starts.
Humanity noticed the weird gender disparity between people compatible with these god machines pretty quickly but who cares.
Then they discover these weird enormous tornadoes roaring around the major impact sites. Naturally, they send people inside to look at what was up. Wow, there's literally what the fuck inside here. Ohh what's this? Weird gravity readings.
Suffice to say, after a little bit of science, humans start jacking Higgs Generators and Higgs Reaction mass from the space contained inside the Tornadoes as fast as they can for free energy forever. 'Better than fusion omfg!' is the general reaction.
Skip a few years, humanity looks to be well on the way to recovery, at least in the areas that people care about, which is the 5 founding UN nations of South Africa, Brazil, India,Australia and China. Then their mining expeditions inside the tornadoes all go silent. A few military convoys get sent in to see what was up. Disappear.
Hmm.
Suddenly, aliens.
Military? What military? The armed forces was literally at the bottom of the UN priority list. The first months are a slaughter of proportions not seen since Impact. Right now, Valkyrie frame are all in the forms of cities and reconstruction vehicles, useless for combat.
These first generation Valkyries quickly ditch their construction materials and synch in military vehicles. Kludged together machines that should have no chance of functioning but do through the Valkyrie Core's upgrading. They managed to hold the line.
People start syncing in military hardware only and begin forming the first proper Valkyrie Frames as we see them, flight capable, dedicated warmachines. They were the first to turn the tide, attacking against Antagonist areas rather than just defend. it was around now that the global draft and other processes were first implemented.
You'd be considered part of the third generation. The UN has gotten its shit together and has a process for creating new Valkyries and plan to wipe out the Antagonists properly.
tl:dr:
Um, here's the actual answer to your question.
1: Valkyrie Cores (excepting The 300) are discovered bare of anything.
2: People synch in machines to them to form the frame,
2.1: Currently, the base machine that is first integrated would be an infantry powered armour with the necessary control software to help neophtes.
2.2: The second thing would be a power generator. Generally fusion.
2.3: Integrate weaponry. The you're done.
3: Give up the completed frames for other people to use.
It's a systematic production line, Valkyrie work on this whilst they are on break from the frontlines. There's no mystique about it.