STC Devices were basically what they are trying to produce now, they are almost 3D printer type tech but an actual forge that can make whatever it is asked to from a list of Standard Templates on its database, most likely in its original form it would have been able to produce another functioning STC device. They have a list of standard, no frills, reliable gear that can be produced from nearly any raw material, making them great for colonies. As the colonies expanded and became towns, then cities, etc, the STCs would have maybe been cast aside as industries grew to mass produce new fancier, less utilitarian designs. What the Imperium wants now is to find these machines, which are usually found in poor condition to try and extract the database designs in its “hard drive”. Think computer forensics on a 25,000 year old hard drive using tech less sophisticated than the computer you are looking at investigating….Snippets and fragments of STC templates are sometimes found, such as Arkhan Land’s Speeder and Raider, or the Rh1no transport vehicle. Sometimes it is varients of these STC templates that are found that allow modifications to the standard vehicle/equipment. But all of these are fragmentary at best, and the dream of finding a fully functioning STC (that hasn’t been corrupted by Chaos as some have in BL novels) to use to produce more of the actual STC machines is very unlikely. Most likely they will find a corrupt part file here and there which they will add to their database, but these are SO rare they will never be able to complete it.

The human psyker gene is a hypothesis that has flown around a lot, from the background of the Old Ones before they disappeared. The old ones created the younger races (not Necrons, not Tau) to perform certain tasks for them and to help them in the giht against the C’Tan, and the evolution of each species was supposed to be guided and looked after to each grow into a role in the galaxy. The Eldar were the seers, they are powerful psykers but not in a destructive way, they were to be more guides that show the way, the Kroork were a brutal warlike race who’s sole purpose were to be the Old Ones footsoldiers, they live for fighting and don’t fear death. Humans were to be the nuclear weapon. Compared to eldar they were short lived and brittle, but their destructive psychic abilities far outclass anything the eldar can muster, but they lack the longevity to perfect it’s use, they are glass hammers in the fight against Chaos and the C’Tan.

Eye of Terror and Slaanesh were WELL after the Dark Age of Tech, it only happened just prior to the Emperors expansion from the Solar System. Space travel was made impossible by slaanesh gestating, the birth of slaanesh made space travel possible again, imagine a warp “big bang”, sending a shockwave through the warp blowing away and dissipating the turmoil in the warp.

Luna became a space station, literally they turn the moon into an armed fortress. In the Garro story he is taken to Luna to be imprisoned, then eventually offered his place in the proto-inquisition.

Primarchs were created first with plans to create their armies, he took the geneseed of the Primarchs and developed the process to make marines. It has been hinted at all over the place with what happens to the the 2 missing legions. One of those is that Russ was sent out to murder them. Some HH fluff states that some of the missing legions were spread throughout the Ultramarines, but that was speculation by a Word Bearer. It is even mentioned in a story of Ullanor that they actually found the 2 missing primarchs during the reconquest, but one of the primarchs shuts the others up with a “we don’t talk about them”.

The Council of Nikaea (interestingly mirroring the name of the Council of Nicaea in 325AD that called all the bishops together to solidify the beliefs and doctrines of christianity into a single form) was not a battle. Nikaea was a planet chosen to host the Council. After the corruption of the warp and accusations of sorcery by Leman Russ against the Thousand Sons and Magnus, the Sigilite convened a council in the name of the emperor to discuss the future of psykers in the legions. As the powers of chaos became more evident it was seem that librarians used similar powers to those used by corrupt enemies, so the primarchs present and the Emperor decide that psychics should not be used. It is made Imperial Decree that the librarians should be closed down and the Librarian Battle brothers cease using their powers and join the normal ranks under pain of death. After this Magnus got in a huff and used his powers to warn the Emperor of Horus’s betrayal, but all it got him was Leman Russ sent to Prospero to kill him.

Sanguinius was also the greatest fighter, literally Horus states the only person that could beat him was Sanguinius, and Horus said Sanguinius should have been Warmaster….the mutation I think stopped him, that and Horus was the first son recovered.

In the HH novel where Magnus uses his covens to Astral Project through the warp he comes to the webway at one point, and I believe it is said a hugely powerful entity aids Magnus in breaching the tunnel in warp space, allowing Magnus to project into the Emperors throne room to warn him about Horus. Unfortunately by doing this it allows daemons to spill into the warp that threaten to over run Terra via the webway portal in the throne room, that is controlled by the golden throne. After this breach it is required that a massively powerful psyker (ie the Emperor) sit on the throne to keep the gate sealed and protect earth from hordes of gribblies. Unfortunately the Emperor is the only person capable of doing this for any significant length of time, with I think it is only Malcador being able to take over for a short time. This is why the Emperor is massively pissed at Magnus, because now Magnus has screwed up humanities hope of non warp space travel but he has also shackled the emperor to his throne room. The significance of Ullanor is hinted that he may have recovered some artifact from the planet that is the final piece he needed to work on his project.

The golden throne and astronomicon are 2 separate entities. The Astronomicon is a choir of psykers that are chosen to sacrifice themselves to ensure the continuation of the Imperium and is located in the himalayas as a part of the Emperors palace. In the time of the great crusade it was powered by hundreds of psykers a day, consuming their life force until nothing remained and they were replaced. The golden throne is the Emperors control module to the webway and later his life support system that keeps him alive by absorbing the psychic lifeforce of thousands of psykers per day.

And finally the Old Ones created the webway with the view to not having to travel via the warp, the eldar just rediscovered it!

Loving this series @warzan, getting my juices flowing for 40k again!