Blackshield - The Sundered and the Black: Almost from the outset, the war of the Horus Heresy was a vast cataclysm and one whose events moved with such quicksilver pace that mystery, supposition, lies and simple ignorance cloaked much of the bloodshed even as it occurred, casting a veil over much that would never be lifted.Though the roll call of Space Marine Legions, Titan Legions, Auxilia regiments and Mechanicum Taghmata that sided with the Arch-traitor Horus and those who remained loyal to the Emperor is largely known and accepted, the full truth is far more complex and far more mysterious than commonly believed.Of those who fell at Isstvan V during the Drop Site Massacre, there were survivors, remnants and fleeing fragments shorn of command and driven half-mad by treachery; from that point onwards they were isolated, alone.These were the Shattered Legions and, while some swiftly returned to the Imperial fold, some did not or would not. Some would go on to wage a bitter war of vengeance alone, some would simply disappear, their fates unknown, their stories untold. But there were others of a darker hue.Despite the paucity of records, accounts of small warbands that were once part of the known Traitor Legions fighting independently persisted throughout the war. In some cases, outcast forces proudly bore their original colours and may have regarded themselves as the true inheritors of their Legions.This can perhaps be explained, at least in part, by persistent stories and evidence long since suppressed of midnight clad warriors in defaced Night Lords heraldry savagely attacking Traitor forces at the liberation of Isstvan III, or of recurring reports of multiple Space Marine strike forces seemingly in the resurrected livery of the Dusk Raiders thwarting the Iron Warriors at Kibron and Malinche's Fall.Another example would be the 34th Millennial of the Emperor's Children, the "Death Eagles", bearing the purple and gold of their parent Legion with pride, refusing to abandon their original heraldry. It is thought that the Death Eagles Millennial clashed with their Traitor kin at Lethe and at Revorthe Keep in the Coronid Deeps, but their ultimate fate, like that of so many others, remains unknown.Likewise also should be considered the long-denied evidence of a Great Company of the Space Wolves Legion bearing the symbol of the Serpent's Eye slaughtering millions at Neo Cadiz in 008.M31, or of a company of Astartes present at the Siege of Mezoa bearing the hybrid arms and panoply of the Iron Hands and Sons of Horus Legions both.These were merely a handful of still-infamous cases, but there are many more unsubstantiated or simply now-forgotten which paint a more complex and uncertain picture of this great civil war than is normally accounted.Further to this, and perhaps an even more sinister enigma, are the persistent reports of Space Marine forces appearing bearing no sign or seal of heraldry or origin at all, or stranger yet, heraldry which bears no mark known during the Great Crusade. A handful of extant accounts, now sealed beyond all retrieval, makes reference to a loosely-termed and non-formal class of Astartes warrior known as the "Blackshields."The majority of Blackshields appear to have been of the Legiones Astartes, though some may once have belonged to other factions. In some cases the term was a literal description, the warriors having obscured the livery of their parent Legion, painting some or all of their armour's panels black to hide all former associations.Although whether the "black" Legionaries were merely turncoats or, as some have whispered, perhaps raised by the Traitors from the chimeric gene-seed of the Isstvan V dead for their own terrible purposes, none can now say for certain.