Ever heard of John Grammaticus? A covert agent of the secret xenos organisation known as the Cabal, John was a powerful human psyker gifted with logokine and pertuality during the Great Crusade. Before being recruited by the Cabal, John lived on Terra and once he even met the Emperor of Mankind briefly, with the Emperor suggesting they should meet again and talk. This never happened though, and soon after John was killed, then reincarnated by an Eldar Autarch and recruited by the Cabal.
Much of John's whereabouts and exploits as an agent of the Cabal during the next thousand years and the Great Crusade remain unknown.
Here is a second encounter imagined between John and the Emperor of Mankind, soon after the Emperor's return to Terra.
Below the Mountain
You sought me out John, here I am
I’m not your ordinary man
You’ve travelled long and far and wide
I’ve watched you ride the cosmic tide
And now your fate I shall decide.
This world is mine, its life; its death
It flows with time’s perpetual breath
An ancient globe; my home (and thine)
A sacred place for all mankind
And those that are to me aligned
Yet you are not to me aligned
You come alone, but you are not
Thought those you serve are but a dot
Indeed, I know of whom you serve
Though don’t be scared and do not swerve
For few exist I can’t unnerve
And you are yet in my grand plot
My early life was lived alone
So long before I claimed my throne
I watched and learned from shadows dark
And seldom sought for change to spark
My past and future soon ‘came clear
A change was needed far and near
And so, I wrought a lightning spear
That man could veer from Chaos’ sphere:
And end an age of rule unjust,
A world so marred by men of lust
I rose and ground them all to dust
Long did I toil in earthy vaults
To mould my men for grand assaults,
Within this fortress, build by knights,
The Order of the Sigillites,
I set about my grand design
A future free from things divine
Where reason rules with righteous wrath
And steer mankind in its great path
My sons will make it all come true
Meanwhile, John, do tell me this:
What is time, and toil, to peace;
Life in pain, one without cease;
Servitude where debts increase;
What are these to restful bliss?
...
Long you’ve been a hidden pawn
Seeking out mankind’s new dawn
First you grew and served in line;
Now you serve a flawed design
Though such pacts you should decline
Faust of old once did as much
Sold his soul and gained a crutch
Ended in a daemon’s clutch
Such is not your fate though scribe
Though you took the xenos’ bribe;
Though you’d die by my mere touch;
Though you have your race defiled;
Though to me you’re like a child;
You still have a role to fill
And your skills will serve you still
Now then, John, this is my will:
Go to those you serve and say
I shall hunt them down one day
Though that day is not today
Though they don’t to Chaos sway
They remain mere xenos prey
They may move their ilk away
From my galaxy and pray
That they've gone so far astray
That my sons won’t make them pay
Fare thee well now, John of old
Go and think on what you’ve sold
Those you serve are wholly wrong
Long they’ve schemed to no avail
Do undo the web they’ve spun
My domain outshines the sun
I perceive things they can’t know
Pure as snow in starry glow
I surpass them thousand-fold
Fare thee well now John the bold
Soon you’ll see all that must be:
I surpass all Kings of old
Like my sons surpass all gold
04.10.2017