The Crucible

This war is a trial. A crucible where we are reforged. Every horror that you see, every waking nightmare, every festering wound and miserable trudge across the no-man's land, every lungful of choking, poisonous gas is an ember to the fire. Here; I will light the kindling and see you remade.
When our gods come, you'll thank me.

The Occultarum have haunted humanity for centuries, infesting their dreams and sighted in moments of madness. Not all see them as devils. The Crucible worship the Devouring Sigil as a god, without ever truly knowing what it is. The horrors they've witnessed on the field of battle and in gas-shrouded trenches filled with dead have scarred them. When the shroud weakens and they see the Sigil in its infinite fractal inferno, they saw a sign of something... Divine.

Impossibly infinite, the Sigil is a glyph of fractal design falling in on itself onto an ever-burning core. It has acquired something rare among the Occultarum - a taste for a particular flavor. Across the shroud, it haunts the battlefields of Cascera for its favored meal of death by violence, of fire and gas in particular.

Reborn in Fire

Spurred by dreams of consuming fire, the Crucible see the war as an ordeal to prove their worth. Humanity is flawed; this pointless struggle proves as much, but it can be redeemed with cleansing flame and purpose. The exact beliefs of the cult, however, are inconsistent. Each cultist who have been touched by the Sigil's impulse or brushed against its presence all have their own ideas of what it was they saw.
But they all agree on one thing; their god demands fire and sacrifice.
The Crucible meet in secret to share their visions in rapturous tales. They test themselves - and others- with fire, and seek to set more and more of Cascera alight. They brand themselves with a crude imitation of the Devouring Sigil, both to show their devotion to their uncaring god and identify others who have seen it.

Burn the World

As of recent, the dreams have become more insistent. Night-terrors haunt the Crucible who live in Purgatio-3 as the shroud is diminished. Their god draws ever-closer and the cult is whipped into a zelot's frenzy.
Now, they prepare and wait for a sign from their god. A sign that all their struggles and all they've endured in this war has had a purpose, that there is more to to the endless days of misery in the mud and rain. They wait with hidden shrines and fevered prayer, ready to set the world on fire.

When the shells fell, he had been fortunate enough to be inside the bunker and could do little but cower as explosion after explosion rocked the fortification. When it ended, he was trapped under tons of dirt and mud in a concrete grave.
He was alone. His only company were the undead who had been stacked in the bunker to meet the next charge, now put to use digging them out.
Then they started to mutter and howl, almost in unison. No matter where in the small confinement he hid or how much he tried to block out the sound, there was nowhere to escape it.
Hunger. Rations soon ran out. There were enough of the crew that one or two could sacrifice an arm or a leg.
The noise wouldn't stop. Even when the stiffs had gone quiet, he could hear something still crawling inside his head. Once the lamp oil ran out, he was left in darkness with nothing but the noise.
Soon, he started to listen. He knew that he had been chosen.

The immense presence of the Occultarum disturb the risen dead. It has become known as the Dirge, a phenomena where the undead begin to howl or moan almost in unison. It can last minutes, hours or days.
There is no reason to it. No matter how much poets wish to spin it as even the dead protesting the senseless carnage of the war. As the Occultarum press against the Shroud, the dead react. Like prey to a predator's shadow.