Voruthrax

The creature can take 3 legendary actions per round, choosing from the options below.

Voruthrax is the product of an obscene fusion between a destructively minded fragment of the Overseer and the raw hunger of the Abyss. Born in a rift beyond the known layers, its first act was to rend the bones of a titan and fashion a citadel from the fragments. Cults that worship ruin swear it is a harbinger of cycles — an agent that clears the old for new horrors. The Abyssal Registry, a consortium of learned fiends and forbidden librarians, keeps a dozen sealed folios describing Voruthrax's birth, but most tomes are soaked in acid or written in melting ink. Legends speak of the Marrowfall Campaign, when Voruthrax marched through the basalt plains of Lesrik and shattered an armada of war-spells in a single day. The Binder Iskotar of Tellun tried to trap the creature within a lattice of iron and prayer, only to lose his hands and half his name; his surviving journals detail strange vulnerabilities — a ritual pattern that will slow it, a promise of a weapon wrought from a fallen Overseer shard. Voruthrax lairs in places where great things were broken: collapsed spires, cratered altars, and the skeletal remains of planar anchors. It feeds on the energies of ruin — devouring artifacts, siphoning ley-threads, and absorbing the desperation of besieged souls. Lesser demons revere and fear Voruthrax in equal measure; demon-princes sometimes bargain with its hunger, others seek to supplant it.

Voruthrax stands taller than a castle gate, a mass of basalt-black muscle ribbed with veins of molten metal that pulse like heartbeats. Its head is an obscene crown of fused horns and splintered bone; rows of glassy, inhuman eyes ringed in rusted iron blink independently. Its torso is plated with broken, overlapping plates that resemble both armor and petrified flesh, each plate scored by glyphs of unmaking. Six limbs end in hands and talons the size of small boats; a barbed tail sweeps like a battering ram. Occasional exposed coils of glowing sinew and smoldering fragments protrude from cracks in its hide. Patches of scorched runes, old bindings and swallowed chains hang from its shoulders, half-melted into the skin. Scattered across the creature's flank are cavities where little ruin-spirits cling, nibbling at power-cores. Scale reference: when crouched in a ruined cathedral doorway, a human reaches barely to Voruthrax's knee. Texture: the skin is coarse and stone-like, the molten veins gleam wetly; burn scars and pockmarks map its battles.