A Soul Harvester is a massive, spaceborne fortress-factory created by the Warpsmiths of the Iron Warriors Legion. It consisted of a central Daemonforge, surrounded by snaking tentacles of hellforged metal.
These parasitic engines would embed themselves deep into a target planet's crust, their boarding tentacles disgorging Iron Warriors into weak points in their enemy's defences.
Meanwhile, the roaring furnace at the structure's heart would feed upon flesh, metal and the souls of the slain in order to spew out fresh Daemon Engine reinforcements from the world's own resources to support the Heretic Astartes in combat.
The fortress-factory's massive tentacles could also be used to transport Iron Warriors troops down onto a world's surface.
Notable Soul Harvesters
- Scarax Krond - More spaceborne factory than starship, this cephalopodic metal monster was powered by an immense Daemonforge. A product of the Iron Warriors' darkest experiments in metallomorphosis and Warp-engineering, it would be the first such creation to be tested in battle during the Talledus War launched by Kor Phaeron against the Talledus System in the Veritus Sub-sector. With its vast alpine ranges and city-sized citadel fortresses, the Fortress World of Ghreddask was the most heavily defended planet in the Talledus System, aside from the capital Cardinal World of Benediction itself. Its seven great hive cities provided billions of souls for the Astra Militarum, and its deep reserves of promethium and super-dense minerals only added to Ghreddask's critical value to the Imperium -- making it an irresistible target for Etrogar. The Scarax Krond latched onto the surface of Ghreddask like an immense parasite, thrusting pseudopods the size of habblocks deep into the earth. These snaking tentacles pulverised their way through rock and stone with siege drills and melta-cannons, before bursting up from the earth within the walls of Ghreddask's citadel fortifications. Heretic Astartes warriors marched forth, unleashing deadly volleys of bolt rounds into their unprepared foes. At the same time, Chaos Knights of House Khomentis lumbered from the gatehouse of Scarax Krond, bellowing oaths of destruction as they set upon the armoured formations of the Astra Militarum. Tank after tank was blasted into molten slag, and arcs of heavy bolter fire obliterated entire formations of Ghreddask infantry. All the while the Daemonforge of the Scarax Krond glutted itself upon the aura of death and destruction. Blasted corpses and twisted wreckages of shattered war machines were shovelled into its furnaces, as Etrogar and his fellow Warpsmiths stoked the hellish fires with the souls of the slain. The Scarax Krond spewed out a tide of Daemon Engines, from scuttling, spider-like Venomcrawlers to hulking Maulerfiends that galloped into battle, eager to mutilate and destroy. Soon the Loyalists were in full flight, retreating to thepolar citadel of Fortress Resolve, where they prepared to make their final stand. Just as the cruisers of the Iron Warriors prepared orbital bombardments that would blast open the last vestiges of resistance on Ghreddask, the Chaos fleet picked up a surge of Warp disturbance. Two enemy capital ships dropped out of orbit -- black vessels, bearing the stark white cross of the righteous Black Templars Chapter. Castellan Dramos led a single strike force detached from the Rutherian Crusade, all that could be spared due to the Black Templars' extensive campaigns elsewhere across the Segmentum Solar on behalf of other Shrine Worlds. Fortunately, Dramos could also call upon a cadre of Imperial Knights from House Mortan, commanded by the dour yet ferocious Sir Dirkwald. Dramos scanned the latest tactical cogitations broadcast from Fortress Resolve. The situation was grim. The Iron Warriors were besieging the polar citadel, pouring daemonic forces against its shield-walls while their siege tanks kept up a relentless bombardment. Yet the true threat, Dramos quickly intuited, was the Scarax Krond. As long as the Soul Harvester's Daemonforge was operational, the Traitors could replenish their forces indefinitely. Strike Force Dawnhammer would deploy in a decisive attack upon the Soul Harvester. The warriors of House Mortan made for the surface of Ghreddask in their fortified bulwark-landers, the heavily armoured vessels shrugging off reams of flak fire. Sir Dirkwald led a frontal assault upon the Scarax Krond. From the parapets of the Soul Harvester, Iron Warriors poured a stream of fire down upon the advancing Loyalists. While the Knights drew the attention of the Chaos defenders, squads of Inceptors descended upon the Soul Harvester like living comets, burning through the upper atmosphere and locking coordinates upon the pulsing shell of the Scarax Krond. They struck home with shattering force, breaching holes in the fleshmetal carapace with demolition charges, even as they fended off flocks of fire-spitting Heldrakes. Castellan Dramos led the assault into the heart of the Scarax Krond, battling through the innards of the iron monster, alongside a retinue of veteran crusaders. This assault team suffered grievous losses as the Iron Warriors assailed them at every turn, but in an act of self-sacrifice that would mark their names in the honour-scrolls of their order, Dramos and his Command Squad managed to detonate a cyclonic charge at the heart of the structure. The resulting Warp explosion swept through the Soul Harvester, immolating Loyalist and Heretic alike and blasting its assembly halls and charnel-factories to atoms. The Scarax Krond convulsed and thrashed its metal tendrils like a wounded animal, but its daemonic furnaces would not be snuffed out so easily. Dramos' sacrifice had bought the defenders of Ghreddask precious time, but the planet's fate still hung in the balance.
- Psychic Awakening - Faith & Fury (8th Edition), pp. 16-17