The Soul Grinder is a titanic marriage of daemon and machine, a greater malevolence bound into a body of iron, brass and adamantium that towers over the battlefield upon piston-driven legs. Unlike the daemon engines built by mortal hands, a Soul Grinder is forged wholly within the Warp, in the black limbo-realm called the Forge of Souls, and so it is a daemon first and a war-machine second. From a hunched mechanical carriage rises a daemonic torso, its many limbs ending in grinding claws and warp-spitting cannon.
Such a body is never freely given. Each daemon that covets a Soul Grinder's form must strike a binding bargain with the masters of the Forge, pledging an endless tribute of souls in payment for its new shell. Every warrior slaughtered by its blades, every machine crushed beneath its tread, is owed back to the Forge as raw material and fuel, and so the Grinder wades into battle with insatiable purpose, harvesting flesh and wreckage alike to settle a debt that can never truly be repaid. Any of the four great powers may claim these engines, and each stamps its daemon-child with its own mark, but all share the same grinding hunger and the same bottomless capacity for destruction.