The battle have ending didn't mean the work was done.
Quite the opposite, in fact as titanic effort to repair equipment and workshop rooms of Castellum began to be obvious to Ætheric Engineer's as they examined their station for damage created in battle.
Never mind the need to find and educate replacements for all Acolytes lost to Demons.
Yet such efforts paled to work that needed to be done by Tech Priests in Noosphere.
For it was the second time in recent years that Demons have struck halls of Castellum.
For some, it means the need to reexamine their battle doctrines, as Warp attacked them in their labs and workshops instead of them going into lost sectors of Mars.
As they came without warning en masse within their defenses, instead of being hunted down in groups over days among the ruins of Mars glory.
And yet, even as such task loomed before them, there was an even bigger one with greater weight and possible reward.
For Demons have attacked Castellum twice.
For Demons have attacked the Ætheric Engineer's seat of power.
For Demons have attacked the Ætheric Engineer's center of their effort for Enlightenment/Knowledge.
For Demons have attacked the Ætheric Engineer's and exposed themselves to all of theirs collection of sensors used for Warp research.
And so that meant there were entire cogitator towers full of gathered data to shift through to see what nuggets of insight they may have.
From the start, it was known much could be gained from such effort.
And yet, such knowledge quickly paled when confronted with the realization of just how much they actually gathered thanks to decades of work upon Castellums structure.
For they had no just simple snapshots of Demons to dive into for data.
But entire sequence of events they have undertaken while on station.
And beyond.
For station's sensors saw the beginning of the attack as Warp began to metaphorically boil right before it surged into stations rooms, spewing Demons into Materium.
They saw as Demons came from within Immaterium into Materium, seemingly materializing from thin air to human senses. Each copy of each other, yet having different Stories to themselves despite common core.
They saw as they battled Ætheric Engineer's defenses overwriting Laws of Physics to enact their Stories upon Ward's refuting them with their own Narratives, even as they were smashed by physical implements.
They saw as defenders surged back in the end, winning and banishing Demons to go back scattered into Warp and yet already starting reforming back before they went too far away in its nonsensical dimensions to detect.
They had entire Vaults of corrupted artifacts to examine. Each with wonderful abilities and more terrible costs to them.
And in each one of those things, they saw one thing in common.
They lost many Acolytes to this work, despite their safeties.
But they had it.
They had the Shape of Demons.
And what was at its core.
BLOOD and WAR
And more importantly, they recognized the edges in Demon's Shapes.
One that cost them they cybernetised psyker to See.
An image that could be reasoned of existing when enough of such Edges were examined to feel out its own Shape.
They lacked enought of such Edges to get its Name.
And so they Titled it The Demon King, the one behind attacks on them.
One that already interrupted their work twice and would for sure try again in the future.
And yet now they had its Servant Shapes and road to get its in future.
So it was time to Sharpen their Edge to kill them.
First, its Infernal Court.
Then to topple Demon King.
So first of all its often a thing especially in 30k that nobody knows of Chaos Gods or their names.
Hell even in 40k there are many Cults or Xenos that don't know Fours Big Names using some lesser titles or distorted names despite their proper Names/Symbol shown to have some serious power by themself.
So getting it know to us would be important, especially as its knowledge and nature of its existence would by time of GC be know to most of Mars and many Forgeworlds.
And for title of Demon King.
Well for Mechanicum there is only one god. Deus Mechanicus/Machine God. And so its Heresy to imply other Gods being a thing. And yet they need to somehow categorize them especially when they reason out other three being around/Names.
So instead of canon clasification of lesser/greater/exalted/God Demons of Chaos they may go for Ars Goetia nobility like ranking of Demons with King at head of its Court.
Also I dont expect any possibility of 'killing' Chaos Gods untill we at least have Divine for everything in all tech trees.
Sorry for double posting but wanted the omake to be alone in post.
