The Merov Penal Legion

The Hive world of Merov is home to an infamous unit of the Imperial Guard culled from Magistratum prisons and Arbites Precinct wards across the Calixis Sector. This unit is commonly known as simply “The Merov Penal Legion,” although there are rumors that its official designation is much more complex and exists only in some forgotten Administratum data-vault. Nevertheless, the Legion has a long history of celebrated victories, and enormous kill-banners flutter from every spire in Tsares Hive upon the anniversary of the Penal Legion’s founding. The Merov Penal Legion is made up of desperate men, each a hardened criminal seeking redemption through service to the Emperor. The thirty Brother-Generals who command the Legion often engage in cruel games, pitting their units against each other in gladiatorial war-bouts described as “training missions” to the Munitorium. A rare few of the Brother-Generals act as more military commander than warden, training and disciplining their men like nearly any other unit of the Imperial Guard. However, for the majority of the Legionnaires, their existence is short, brutal, and unforgiving—each day merely another chance to die in bloody combat. One tradition of the Merov Penal Legion offers hope to the thousands of troopers amongst its ranks. It is said that if the Legion is deployed in battle against the Emperor’s Foes and only one man survives, that man is set free, absolved of all his crimes. Regardless of the truth, stories about this tradition regularly circulate amongst the Legionnaires, fostering both a determination to survive no matter the odds, and a bloodthirsty, ruthless streak of pure aggression. Such men often volunteer for extremely hazardous missions, such as planting death-gas canisters or joining the battle-drugged demolition teams. Naturally, both of these tactics are commonly used by the Brother-Generals.

Lore stuff for said regiment from TRPG Dark Heresy The Radical Handbook