From Warhammer 40k - Lexicanum
The spell both succeeded beyond Ahriman's wildest dreams, and was an incredible disaster.
Less Fewer than 100 of the Thousand Sons who possessed psychic powers had them greatly augmented {{Fn|3}}; however, the majority of the Legion's Marinesmarines, who had little comparatively less (or even no , in some cases) psychic ability, had their physical bodies reduced to dust, trapping their spirits in their armour, the joints of which were sealed magically and allowed the spirits no way of escaping. Thus were the Thousand Sons rendered immune from mutation, and also damned for eternity.{{Fn|1a}} Since Ahriman's spell was cast, the Thousand Sons' armies have been composed of these [[Rubric Marines]], which are dependent on nearby [[Sorcerer]]s to guide and motivate them.{{Fn|1b}}
Magnus was enraged. Ahriman was exiled along with the rest of his conclave, and Magnus set about the conquest of the galaxy, vowing to see the [[Imperium]] burn.{{Fn|1a}}
