Changes

Baron '''Vardus Praal''', Imperial governor of the Isstvan system, had risen in revolt against the Imperium. The Emperor and the [[High Lords of Terra|Senate of the High Lords of Terra]], ignorant of the change in Horus, charged the Warmaster with crushing this rebellion. Under his command were four [[Space Marine Legion]]s; his own [[Sons of Horus]], the [[Emperor's Children]] of [[Fulgrim]], [[Mortarion]] and his [[Death Guard]], and the [[World Eaters]] led by [[Angron]]. Horus and these Primarchs had fallen to Chaos and took this opportunity to purge all suspected Loyalists from their Legions.

Afterwards, he ordered a massive [[Virus bombs|Virus bombardment]] upon the planet. However, Captain [[Saul Tarvitz]] of the Emperor's Children, working on a hunch, had managed to remain in the fleet. To his horror he discovered the planned bombardment and managed to seize a Thunderhawk to save his betrayed brethren. The bombardment caused 16 million deaths among the inhabitants, every Loyalist that couldn't reach shelter in time (World Eaters suffering the greatest losses) and the utter consumption of all organic matter upon the planet. Thanks to Tarvitz's warning a few hundred loyal Space Marines managed to survive inside airtight bunkers and bomb shelters. As the putrid gases resulting from the rapidly decaying organic matter filled the atmosphere, Horus ignited a firestorm on the planet which melted the hives and razed the cities. The psychic death scream of the 16 million is said to have been louder than the [[Astronomican]].