A Warsinger was a type of Renegade Human psyker warrior once indigenous to the former Imperial Civilised World of Istvaan III. The Warsingers as a sect were dedicated to the service of the Chaos God Slaanesh.
One of the more dangerous local sects, the Warsingers could emit sonic screams, blasts of damaging sound waves and take flight through the use of strange relic-technology.
These abilities were the result of mutational "gifts" provided by the power of their Chaos patron.
The Warsingers were instrumental in the corruption of the Istvaan System and its people by Slaanesh. They spread this corruption to the world's new Planetary Governor, Vardus Praal, after the Imperial conquest of their world.
The Slaanesh-worshipping population of Istvaan III were used as sacrificial pawns in the Warmaster Horus' scheme to amass those forces loyal to his intended rebellion against the Emperor of Mankind without suspicion, and also rid his own Sons of Horus Legion and those Space Marine Legions of his closest allied Primarchs of those within their ranks whose loyalties to his cause were suspect. As such, when word came to the Warmaster of Vardus Praal's rebellion against the Emperor, he ordered the Imperial campaign that would be remembered as the Istvaan III Atrocity.
Within only solar hours of the start of the Imperial campaign, the rebellion was in tatters. Vardus and most of the Warsingers were slain with all of the Imperial invasion force's objectives secured and tens of thousands of the enemy dead in the wake of the assault.
The Loyalist Astartes proved victorious, but were betrayed when a cascade of terrible Life-eater Virus Bombs fell upon the smouldering planet, launched by the Warmaster's orbiting fleet. This doomed both rebels and Astartes alike to an agonising death.
When the Life-eater virus was unleashed upon the world, the Warsingers tried to comfort their people, but were quickly slain by its effects.
- Codex: Chaos Space Marines (6th Edition), pg. 9
- Codex: Chaos Space Marines (4th Edition), pg. 12
- The Horus Heresy - Book One: Betrayal (Forge World Series) by Alan Bligh, pp. 39-41
- Galaxy In Flames (Novel) by Ben Counter