"None of our fellow Legionaries hesitate to bring up the stigmas associated with our origins. Butchers they call us. Bastard spawn of a mad tyrant. They neglect to mention how many of their ranks our forefathers gutted like Grox. Must be nice, having such a selective education regarding the history of the Legions."
― Don Goge, commander of the 4th Syndicate
Raised by the corrupt will of the forever condemned High Lord Goge Vandire during the infamous era of the Reign of Blood, the Smoke Jaguars Legion were part of the infamous 4th or "Shadow" Founding, created to serve Vandire's every murderous whim. Though originally conceived in secret deep in the dark Gene-Vaults and select asteroid complexes of the Oort Cloud, the Smoke Jaguars would go on to become the most infamous examples of the Traitor Lord's Legions.
Cold and brutal in the extreme, the Smoke Jaguars were some of Vandire's favored pawns, deployed to commit his most heinous purges. Astartes Commanders, would-be reformists, and even whole planets fell to the murderous Chainswords of the Smoke Jaguar's Shadow Legionaries. Their ruthless forces never left witnesses, such was their cold savagery. As such, the Smoke Jaguars caught the Legions loyal to the Primarchs utterly by surprise in the ensuing civil war between Vandire's corrupted supporters and the true Loyalists to the Imperium. The Legion's bloody handed actions at the infamous Vesuvian Wars and the dreaded Caltohaust Crusade made certain that of all the Shadow Legions the Smoke Jaguars were held most in contempt by the Primarchs and reformist Sebastian Thor following the murder of the Traitor Lord.
For their gleeful fratricide and considerable reluctance to denounce Goge Vandire, the Legion would forever be marked with a stigma for evil and brutality. Still, the Imperium had need of warriors following Vandire's ruinous Reign of Blood, and so after sufficient penance was leveled at the Smoke Jaguars, they became one of the foremost elements in the swift and bloody execution of the remainder of the slain Traitor Lord's supporters. From then on, the Smoke Jaguars have served as a potent and ruthless tool of the Imperium's wrath, striking dread into the hearts of foes with their methodical savagery and fanatical dedication to the God-Emperor of Mankind.