Chainrasps were the criminals of the Mortal Realms: cutthroats, poisoners, oath-breakers, and thieves who died in irons or deserved to. Nagash's verdict binds them in the spectral echo of their fetters, leaving their malice intact while taking their freedom forever. They come on in moaning floods, gaol-blades and cudgels swinging, each spirit shoving against its chains toward the warmth of the living.
Individually a chainrasp is a feeble thing, but no one ever fights one chainrasp. They attack as a horde, drowning shield-walls the way a rising tide drowns a sandbar, and they are herded by Dreadwardens — gaoler-spirits whose candle-topped staves draw the malignants after them like moths. The horde's private cruelty is this: each chainrasp believes that if it drags enough souls into the dark, its own chains might finally be struck off. It is a lie, and Nagash lets them keep it.