Primarch blood.
It was a tangible and precious substance. A single drop was enough for the Biologis to unravel countless genetic mysteries, allowing many legions on the brink of destruction to be reborn.
Warp essence.
It was an abstract and dangerous concept, slowly seeping from the Primarchs' souls in wisps before ultimately entwining with every inch of their flesh and blood. Even The Emperor had never fully understood this power, and the Primarchs who had hastily unleashed their Warp essence in the final battle were equally unfamiliar with it.
The abstract collided with the tangible, crossing the barriers between the rules of one world and another through the Subjective One's immense power to make his words reality.
When an existence and power system that did not belong to this world passed through that gate, its unique fluctuations stirred the ancient legends scattered across Terra.
Terra's civilization was like a lone boat floating upon an ocean called the unknown.
Ursus's iron tide and Sami's snow witches drove the cold from the northern frontier.
Sacred gunlances and the lanterns of faith watched over the terror of the southern seas.
The East was shrouded in ethereal clouds and mist, with dragons and ghosts guarding the gates.
The West was an endless sea of sand, where the ancient and the newborn converged.
Within the deep sea feared by Aegir, ancient and prosperous beings sensed an unfamiliar scent drifting in from the land.
Even having temporarily lost the guidance of their supreme god, they could still keenly understand that this thing would allow their race to flourish to unimaginable heights.
Every possible and impossible region would henceforth become fertile ground to nourish them...
Expand the domains of life, increase the quantity of life, enrich the genes of life...
This was their instinct, the only undertaking