Originating on the world of McKay's Folly, the Glory of the Blood cult were responsible for multiple killings in the Hives dotting it's surface. When a warband of World Eaters attacked, it was this cult that rose in insurrection, hampering the Planetary Defense forces from mounting a defense.
It is unknown just how many innocents died thanks to their sabotage. When the World Eaters finally tired of their sport and departed, the cult vanished with them.
Private Riggs is a tragic part of the Cults history. Blinded and deafened in the opening stages of the World Eaters invasion, Riggs opened fire upon his comrades, believing them to be the enemy. Taking advantage of his infirmities, the Cult swept him up. Even now he murders loyal soldiers of the Imperium, all the while believing himself part of a Holy Crusade against the Emperors enemies.
The Stalker in the Dark is known as the most prolific serial killer to ever strike on McKay's Folly. Responsible for hundreds of horrific deaths, none have glimpsed the face beneath his mask, it's glowing red eyes the last sight of his innocent victims.