The Book Of The Stigmartus
“And the Lords of Khazant, weak and riven with strife, were cast down by the forces of the Corpse God. With their fall, world after world fell with them, and millions burned in the Ecclesiarchy’s sacrificial flames. The True Gods saw that their Champions had failed them, and they left the weak to perish. For a year the Corpse God’s armies pressed further and further towards the Charon Stars and towards Hadex itself, and there were none to stop them.
At length, the Gods spoke unto a Warrior of the Charon Stars. They whispered to Him secrets of the Warp, and bade Him raise an army against the Imperium of Man.
He scarred his flesh to mark his ascension, remaking Himself a changed avatar of blood and pain and mortification. So came to be Elak Sarda, who stands at the Right Hand of the Gods."
The Book of the Stigmartus