Grey Knights - A Blade Against Chaos: The Grey Knights are the most mysterious of all the Imperium's warriors. Their creation was the culmination of a plan conceived in the dying days of the Horus Heresy, hidden from even the Emperor's armies lest it be uncovered by His foes. Even now few in the Imperium of the 41st Millennium know of their existence, and those that do possess only fragments of the truth. Legends and myths surround the Grey Knights, and those tales told about them are filled with broad misconceptions and fanciful lies.The vast hordes of Humanity know nothing of the Grey Knights, and the handful of Imperial citizens that have heard the name uttered assume them to be an arm of the much-feared Inquisition or a Chapter of the mythical, transhuman Space Marines.  Some of the stories and fables taught by the Adeptus Ministorum hold the barest hints of the existence of the Grey Knights, but they are portrayed as silver-armoured angels, ghostly manifestations of the God-Emperor or shimmering reflections of the saints themselves as often as not.Those Imperial soldiers that have fought alongside the Grey Knights and retained both their lives and their minds recall them only as Astartes of an unknown Space Marine Chapter, their unique weapons and psychic powers attributed to forgotten technology and tactical doctrine. Other Space Marines know better should they see a Grey Knight in battle, but are wise enough not to dwell long in thought about these mysterious warriors.Legend has it that the Grey Knights were founded on the order of the Emperor Himself, in the final bloody days of the Horus Heresy, just before the start of the Siege of Terra. The Emperor knew that the time was coming when He would have to face His traitorous son Horus and that He might well not survive. However, He foresaw that, even if Horus and his armies were defeated, the power of Chaos would remain an ever-present and constant threat to Humankind.His greatest warriors, the Space Marines, had proven unfortunately corruptible to the temptations of the Dark Gods and so the Emperor set out to create a new transhuman soldier in His bid to continue to protect Mankind, even from His own gravest mistakes. This new breed of Space Marine would be far stronger of will than their brothers, and unwavering in their loyalty to Humanity, able to stand naked before the power of the Warp and survive unscathed.In this dark time the Emperor turned to Malcador the Sigillite -- His most trusted servant and the first High Lord of Terra and Imperial Regent. Malcador was a powerful psyker, lore-keeper of the fledgling Imperium, and had stood at the Emperor's side since before the start of the Unification Wars. He was charged by the Emperor immediately after news had reached Terra of the Warmaster Horus' betrayal during the massacre of the Loyalist Astartes on Isstvan III, to gather a group of dedicated Imperial servants whose loyalty, courage, and strength of mind was unquestioned.As the Emperor prepared for the final battle with Horus, Malcador crossed the divided Imperium, searching corpse-choked battlefields and worlds drowning in blood for those the Emperor sought. No other person save the Emperor Himself could have been given such a task and hope to complete it. However, Malcador returned to the Imperial Palace just before Horus' forces laid siege to Terra. Only the Sigillite's psychic mastery and knowledge of the hidden ways into the palace allowed him to slip through the Traitors' growing blockade around the Sol System to reach the Emperor's side.When the Master of Mankind looked upon those Malcador had brought before him He knew that there was yet hope for Humanity. Twelve in all had been gathered, four noble lords and governors of the highest order, complemented by eight Space Marines, though each group met the Emperor separately at different times in the final days before the Siege of Terra began.These eight selected Space Marines all possessed paranormal skills as psykers that had been kept dormant as required by the edicts of the Council of Nikaea -- the council had ruled during the Great Crusade that the use of psychic powers was forbidden to Space Marines because of the dangers innate to manipulation of the Empyrean. These warriors had all willingly cast aside their former loyalties to their given Space Marine Legions and primarchs, either because of the corruption of these Legions by Chaos, or because they realised that loyalty to the Emperor required them to sacrifice all ties to their former battle-brothers.All had served for a time with the Knights-Errant, Malcador's cadre of independent Space Marines that had served as his special agents throughout the course of the Horus Heresy. That some of these battle-brothers came from Legions that had turned Traitor proved the depth of their loyalty to the Emperor, for there can be no greater challenge for a Space Marine than to defy the word of his primarch.After meeting the candidates, the Emperor is believed to have responded, "Malcador, you have judged well. These eight Space Marines do indeed have a vital role to play in the future of the Imperium, though veiled in secrecy will they be." Content that His plans could proceed, the Emperor bade Malcador and his charges leave for Titan, the moon of Saturn.The Grey Knights were created alongside what later became the Inquisition and their goals were intertwined. They would be the staunch allies of this new organisation, fashioned in the image of the Space Marine Chapters, their battle-brothers augmented by the Emperor's advanced science and genetic experimentation.Blessed with both transhuman physiology and the most advanced Imperial weaponry, the Grey Knights would be the most elite force of the Adeptus Astartes. However, it would not be enough for them merely to be strong of body and skilled at war, though in this they surpass even other Space Marines. To fight the Daemon the Grey Knights would need to be unusually pure of heart as well, with an unblemished soul in which the corruption and temptations of the Warp could find no purchase.