The Cronos Parasite Engine is a floating horror wrought in the flesh-forges of the Haemonculus covens, a hovering vessel of blades, tubes and questing tendrils built to feed upon pain itself. Where it drifts, the dying give up more than their lives, for the engine drinks the raw psychic essence of their suffering and stores it within its bloated frame.
That stolen anguish is no idle trophy. The Cronos channels the harvested agony outward, invigorating the Drukhari coven-fighters around it, quickening their reflexes and dulling their pain so that wracks and grotesques fight on through wounds that should have felled them. In this way the engine turns the battlefield's misery into a weapon, each death it witnesses making its masters stronger.
When roused to violence the Cronos lashes out with a spirit-leech tendril and a spirit vortex, tearing the souls from those nearby and adding their torment to its store. It is a creature of pure appetite, mindless and insatiable, and the Haemonculi who craft such things regard them with the fond pride of an artist admiring a particularly efficient instrument of harvest.