Chaos Cult - Strength in Darkness: Warp cults had two primary weapons to bring to bear against the Loyalists. The first was simple numerical advantage, for the tendrils of heresy had spread far and wide in the years preceding the betrayals in the Isstvan System and by the time of the Battle of Calth, the Traitors were able to call upon unnumbered hordes of devoted cultist foot soldiers.Numbering among the subservient foot soldiers loyal to the Word Bearers and Sons of Horus in particular, Traitor war fleets were often accompanied by carrier vessels whose dark, stifling cargo holds were crammed full of cultists devoted to their cause.While many Warp cults rose up as discreet bodies, each holding their own idiosyncratic beliefs and practises, once swept up in the massive sector-wide advances of the Horus Heresy, they were soon subsumed into a gestalt mass of frenzied Chaos devotees bearing all manner of equipment and clothing.The second is that numbers alone are unlikely to have granted these forces a decisive advantage, and it was in the sphere of the esoteric and the occult that their true strength was to be found. At Calth and in many other conflicts, the Warp cults served as part of a grand conspiracy, one in which stratagems beyond the grasp of the Loyalists were frequently employed.By way of Warpcraft and forbidden psionics, Warp-magi could cause the Empyrean to bleed into reality; they could assail the foe with the sanity-shattering wails of damned souls; they could make the stars go out and cause horrifying visions to burn across the night skies.Most terrible and potent of all were those magi who, by way of pacts with the unnameable denizens of the beyond, could call forth legions of fiends, things dubbed "Daemon" by those few who witnessed them and survived to recount the nightmare.Time after time, the Warp cults showed themselves willing to sacrifice their own lives in abominable mass sacrificial rituals to bring these creatures into being on the material plane, and the Loyalists learned at a high price indeed that in slaying the massed hordes of Warp cultists, they might simply be hastening the arrival of a second wave of Warp-born Daemons, a foe which few mortals and only the most stoic of the Legiones Astartes could hope to defeat.In the panoply of war however, the majority of Warp cults were almost entirely deficient. Unlike the Imperialis Auxilia regiments that declared for Horus, the countless Warp cults rarely had any access to military stockpiles before they rose up against the Imperium. Even once counted amongst the ranks of the Traitors, most cult bodies were afforded only the most limited access to Traitor supply chains.In reality, most cultists armed and equipped themselves by looting the bodies of the fallen, both Traitor and Loyalist, giving them a motley and ramshackle appearance made all the more outlandish by the occult formulae and Warp-based heretical runes scratched into weapons and daubed across flesh and armour.For all their undoubted value to the Traitor Legiones Astartes, the fate of the majority of allied Warp cults was the same on many battlefields. Their lot was to be expended as ammunition in the service of the Warmaster. They were frequently deployed but rarely re-deployed unless they could extract themselves from a war zone by their own efforts.Traitor Legiones Astartes commanders gave little or no heed to cultists' well-being and regarded them as entirely expendable.Until the Siege of Terra, this fact was never made more starkly clear than at Calth, where hundreds of thousands of deluded Warp cultists were committed, only to be abandoned, their deaths but one element in Lorgar's far-reaching and unfathomable ritual to bring about the Ruinstorm.