"Down from the skies it came, buzzing and clicking, a bristling profusion of antennae and a glinting carapace the colour of dried blood. We thought we had more pressing concerns, for to repel a Commorrite invasion is to fight against a hurricane of blades. Bolters spat fury. Then my brothers began to fall, soundlessly, to the ground. Brother-Captain Alkon was unresponsive. I wrenched off his helmet to find a wizened skull leering back. It was then the xenos attack doubled in its force..."
The Cronos Parasite Engine is a Drukhari war construct and Engine of Pain. It resembles a great, biomechanical insect or spined deep-sea abomination, its burnished shell covered in bristling antennae and twitching vanes. Though it is employed to the same end as the Talos Pain Engine -- to torture and destroy -- the Cronos is an even more extraordinary machine.
Through the blend of alchemy and science practised by the Haemonculus Covens, the Cronos is able to drain the very life essence from its victims using a variety of esoteric apparatus. What remains of its prey when the vile creature has drunk its fill is a testament to the diabolical skill of its creators, for in its wake a Cronos leaves little more than grey and shrivelled husks.
The Cronos has earned a grim reputation amongst those members of the "lesser races" who have fought against it and survived, for this horrific product of the Haemonculi's art can generate a feedback loop of negative energy that siphons the life force of those caught in its field. To the onlooker, a victim of the Cronos' invisible attention seems to age at an incredibly rapid rate, their body wrinkling and rotting until nothing is left but an ancientlooking cadaver. In addition, each Cronos has multiple tentacles wrought from metal, flesh and nervous tissue dangling from its forelimbs and underside, which are similarly capable of draining the animating essence of those they strike.
These beneficial effects are by no means confined to the Covens, however; all Drukhari can absorb the life forces purloined by the Cronos, becoming stronger and more vital every time the beast successfully feeds. Archons who expect a raid to become protracted will pay handsomely for such an Engine of Pain to accompany their mission, for should their warriors become bogged down in a roiling battle, a nearby Cronos can not only sustain them through grievous injuries, but drive them to such heights of murderous passion that the scales are quickly tipped in the Drukhari's favour. Even within the Dark City, it is not uncommon for a wealthy Overlord of a Kabal to permanently keep a Cronos close by, so that it can be set upon disloyal servants and potential usurpers.
When a Haemonculus enters realspace to gather living fodder for their oubliettes, they will regularly take a Cronos with them -- not only to bolster their own vitslity in battle, but also to observe the effects different harvested souls have on their other fleshy creations. Indeed, countless sentient species have been eradicated over the millennia for the simple reason that their spirit essence proved especially invigorating to a particularly genocidal Haemonculus.
Some Cronos are further modified by their Haemonculus creators to bear other soul-draining weaponry, such as a Spirit Vortex or Spirit Probe.
The Spirit Vortex is a spiral-etched device that hurls out massive amounts of negative force across great ranges, ensuring those who try to keep their distance from the Cronos do not avoid their grim fate, while the Spirit Probe takes the shape of a fluted and crystalline device that hangs from the Cronos' head like the proboscis of an alien insect. The Cronos drives this hollow tube directly into those it has grasped in its tentacles, ingesting their life-force through more direct means.
The stolen vitality of the machine's victim is then magnified within its shiny carapace, fed through its ribbed capacitor-valves and projected from its resonator vanes once more. Pulsing waves of spirit-essence flow outward to those Drukhari standing near the Cronos -- usually its Haemonculus master and his ghastly carnival of monstrosities.
In this way the metallic monstrosity nourishes and rejuvenates those nearby, driving them on to ever-greater feats of destruction. It is this ability that has led the superstitious denizens of the Imperium to refer to the Cronos as "time-thieves," for they steal youth and vigour from their prey and gift it to their sadistic keepers.
- Codex: Drukhari (8th Edition), pg. 73
- Codex: Dark Eldar (5th Edition), pg. 41