Warhammer 40k: Imperium Shattered

Beneath the Desolation Plains, the Ashen Tunnels weave a sprawling, suffocating labyrinth of ancient maintenance corridors and forgotten underhive passages. Choked with ash and soot from centuries of burning waste above, the tunnels are hazardous and treacherous. Their walls are cracked, leaking industrial runoff that hisses when it meets the warm ground. Hidden by shadows and heavy smoke, the tunnels are infested with Chaos Spawn and warped anomalies that can twist reality. Often used by smugglers and cultists to move unseen, these tunnels offer perilous shortcuts beneath battle lines. At their heart lies the secret lair of Sythra Vorissa, a Tzeentchian sorceress who uses the labyrinth to manipulate conflict on the surface, orchestrating assassinations and spreading madness through whispers in the dark.

Dark, narrow tunnels carved into the rock, with the faint, flickering glow of warp distortions illuminating damp walls covered in creeping shadows and occasional grotesque fungus, adorned with remnants of long-forgotten artifacts strewn across the floor.