Do not ask which creature screams in the night. Do not question who waits for you in the shadow. It is my cry that wakes you in the night, and my body that crouches in the shadow. I am a God and you are the puppet that dances to my tune...”— Lord Scar
Lord Atheon Scar is the founder and current leader of the Cazaclaw Oldguard, and trusted advisor of Lord Horus.
Half a millenia ago, when Lord Horus first appeared leading the Great Unification, Lord Scar was already at his side, a shadow in the darkness behind him, a constant whisper in his ear. Whilst Lord Horus' army gained strength due to the extreme success of the early phases of the campaign, rumours began to spread. Lord Scar was constantly at his lieges side when attending any public addresses, relenting only in his whispered guidence whilst the speeches themselves was made. The newly gathered legions was suspicious of this "man" that was at their liege's side. Lord Horus had been foretold centuries before by the great scribes of each hive, but nothing was ever mentioned of this stranger clad in the blackest cloth and metal. The most treachourus of the newly gathered Legions started amassing spies, intending to uncover the identity of this man. They quickly found out that nothing could be gathered, especially from the stern and mindlessly devoted members of the Legio Primoris. Another thing they quickly discovered was the attrition rate of their spies, as not a single spy they ever sent returned.
One night, shortly before the great battle afore Hades Hive, every single one of the treachourus Legio Primarchs got a message from one of Lord Horus' messengers, stating that they were to gather in the great feasting hall for a tactical assembly. They found this strange, as the plan for the battle already was established, but at Lord Horus' personal command they could not refuse. They all gathered in the feasting hall, suspicious to only see each other. A short while later, a man steps in, clad in black plate, wreathed in robes black as oblivion itself. The man calmly stood upon the table, and announced, in a voice not spoken, but imprinted into the mind itself; "Here, dear Primarchs, is where you draw your last breath.". The Primarchs, great and proud warriors all, were outraged, and all drew their blades, approaching the man. Towering before him, the greatest of them all, Primarch Xereus, raised his blade, and then froze, deathly still. He tried to strike down with all his strength, but his own muscles dared not respond. The man slowly floated, but an inch from the ground, forward to the great beast and whispered into his ear; "Enjoy that last breath, mortal..." before striding straight through him, Xereus' great body dissolving into ashes. The great doors of the feast hall slammed shut, and the fire died. The Legions of the traitorous generals had amassed out side the great hall, waiting for their lords to exit. When the great doors opened once again, a great cloud of ashes slowly spread out against the soldiers, covering everything in a thin layer of black dust. Out from the ashes strode the man, a hatred burning from behind the his plate, from inside himself. The tension in the air was palpable, and even the stoic Cazaclaw soldiers waited, uncertain if they should attack or not. The man strode forward, his voice echoing through the minds of the assembled armies; "Your beloved Primarchs are all dead, gone, forever lost to you. They were traitors to the cause of our beloved Lord Horus, and therefore had to pay the price. They were all shown the might of a God, and were found lacking. Prepare to join them...". What happened later is unrecorded in history books, but several different accounts from eye witnesses claim a horde of riders made from nothing but smoke appeared, destroying the traitor legions, whilst others say it was all smoke and mirrors and the loyal Legio Primoris laying in ambush. What is true is uncertain...