Chaos Knights - Iconoclast Houses: The pilots of the first Iconoclast households had already Become before the start of the Horus Heresy. The enormity of the Imperium's fracturing had devastating effects on those Knight houses whose allegiances lay with the Traitors.As the heretical war spread across the galaxy, the ghosts within hundreds of Thrones Mechanicum howled in anguish, their imprinted spirits tortured by the impossibility of upholding their honour in the face of their Traitor masters' deeds of betrayal whilst maintaining their loyalty.The neural outcry was such that some Nobles were driven insane by it, while others suffered gruesome cerebral haemorrhages. Others still followed blindly into damnation, claimed by that most insidious trap of believing honestly that those to whom they had sworn their oaths fought for a just cause.The vast majority of turncoat Nobles, however, were subjected to immense torments. They were ceaselessly assaulted by feelings of shame and hatred, their every negative emotion amplified and echoed by the ancestral spirits of their Thrones Mechanicum.According to the Code Chivalric, failure to perform one's duty is a transgression that can only be absolved through selfless service. As such, these Knights fought all the harder for their treacherous lieges. At the commands of their heretical lords, lances of Chaos Knights tore bloody paths through the Imperium's armies.Once-honourable Nobles led attacks to desecrate cities and enslave the populations of entire planets. Kilometres-high statues dedicated to the Emperor were toppled by Knights' ceaseless bombardments, and in their place profane monuments were erected to glorify the cruelties of the Dark Gods.These attempts to quell their self-loathing through unquestioning service only added further fuel to the fire. The Knights were compelled towards greater extremes of brutality and further depths of depravity, and with their every debased action the screams of their Throne Mechanicum grew louder.Over time the Chaos Knights became unrecognisable as the valiant warriors they once were. Some had transformed into incarnations of carnage. They hacked their way through the steel and flesh of their foes, seeking only to drown their unrelenting anguish in oceans of blood.Others became agents of instability, their motivations and allegiances upended constantly by the hateful tempests that raged in their souls. The growing insanity that festered inside each Chaos Knight corroded their notions of chivalry, twisting concepts of honour and duty into new and nightmarish ideals.These Fallen Nobles justified the most heinous atrocities they committed in the Traitors' name, reasoning that they had been bred to be exemplars of virtue, so every action they took must therefore be virtuous. Whilst incinerating the defenders of an Imperial bastion, a Renegade Knight would conclude that such measures must be necessary, for otherwise their codes of virtue would not allow them to immolate their victims.By the same grotesque logic, if roasting alive a hundred Imperial soldiers was an act of honour, then there could be no greater honour than seeing the entire galaxy set ablaze.The tortures endured by each Chaos Knight pilot served to permanently corrupt their Throne Mechanicum. Upon their death, the imprinted remnants of a Fallen Noble remained in their Throne, where their twisted visions of virtue spread to the other spectral echoes like a rampant digital infection.No longer would the Throne serve to shield the pilot from corruption -- it now fed the depraved desires of those who would bond with it. Bloodlust, sadism and psychosis were fostered in the lines of Fallen Nobles that flowed from the first Chaos Knights, giving rise to the tyrannical warlords of the early Iconoclast houses.Iconoclast houses are defined by the malice and madness that led to their corruption. In place of honour they pursue only conquest, destroying whatever enemies stand before them to expand their tyrannical domains. Many have long histories of depravity that stretch back for thousands of years, though new Iconoclast houses can be formed wherever the taint of the Warp takes hold.