The Armatus Necrotechnica was an ancient and powerful anti-psyker device utilized by the Imperium during the Great Crusade and Horus Heresy eras. This technology is capable of harnessing the stolen energy of sentient life to power engines of mechanical destruction and repair.
These secret devices of necro-technic engineering were among the fel technologies once bound within the sealed vaults of the Primarch Ferrus Manus. Outside of the Iron Hands Legion, the knowledge of their very existence was limited to prohibited circles of the Emperor's own household and used as part of the construction of the Warlord-Sinister Psi-Titans.
How they were later spread is unknown, but must surely have involved the defection or capture of high-ranking Terran artificers from the Imperial Palace or the secretive tech-clades of Luna, for it is thought improbable that even those Iron Fathers who raided the X Legion's storehouse of technological secrets, the Vaults of Mimir, would dare to unleash such dark techno-heresy upon the galaxy.
Whatever their origin, these foul technologies were witnessed on several battlefields as the Horus Heresy drew towards its climax, both on Traitor armour and among the ranks of Ferrus Manus' grief-maddened sons of the shattered Iron Hands Legion.
- The Horus Heresy - Book Eight: Malevolence (Forge World Series) by Neil Wylie and Anuj Malhotra, pp. 300-301