Deliverers were specialised units used exclusively by the Raven Guard Legion who were composed of Terran-born Legionaries arrayed in bulky Cataphractii Pattern Terminator Armour, who were grim aspect and wielded an array of fearsome weapons not usually favoured by the subtle tactics of the XIXth Legion. They were highly adept at close-range shock assaults from both aerial transports and teleport deployments. Through rarely called upon by their Primarch Corvus Corax, they were nevertheless loosed upon only those foes who proved extremely tenacious and had earned the Primarch's ire.
Even in the days before the coming of Corvus Corax, the XIXth Legion was renowned for its skill at fast strikes and hit-and-run raids. As with many Legions, this skill quickly became ingrained into the nascent Legion as they came to be employed more and more in these roles, eschewing the massed battles and attritional warfare favoured by other Legions. As well as moulding the tactics of the XIXth Legion, this tendency also affected the Legion's armoury, which swiftly found itself biased towards light attack vehicles and those marks of armour that favoured agility and stealth over bulkier plating.
The earliest marks of Terminator Armour were no exception. Despite the favour shown to the Tactical Dreadnought Armour project by Horus himself, who acted as patron to the XIXth Legion in the absence of their Primarch, many of the warriors of the XIXth were ill-disposed towards the slow and bulky Cataphractii suits. Some did adopt their use, mainly those chapters who had long served in the shadow of the Luna Wolves siege and heavy assault companies, becoming adept at close range shock assault from both aerial transport and teleport deployment.
The Legionaries of the XIXth Legion came to refer to these detachments as "Deliverers." In the wake of Corvus Corax's return, the Deliverers were rarely called upon by the Primarch. Most were assigned to distant Crusade fleets and those who remained at Corax's side became the avatars of his carefully controlled anger, loosed when an enemy proved itself worthy only of utter destruction.
- The Horus Heresy - Book Three: Extermination by Alan Bligh, pp. 137, 150-151