The original Therion Cohort was an illustruous regiment of the Imperial Army, one that has had the honour of fighting alongside the Emperor of Mankind Himself during the 30th Millennium. Attached first to the 376thand then to the 27th Expeditionary Fleets under the Raven Guard Space Marine Legion and the command of the Primarch Corvus Corax, himself, the Therion Cohort were sacrificed in a diversionary attack on the forces of the rebellious Warmaster to allow the extraction of what remained of the Raven Guard Legion in the wake of the Drop Site Massacre. The reconstituted and severely augmented Therion Cohort would then honour their oath of servitude and allegiance to the Emperor and officially declare for the Golden Throne. Like their tutelage Legion, the Therion Cohorts decided not to si