Uncharacteristic of a Codex Chapter, Black Templars Neophytes are employed as frontline soldiers rather than being used as a separate Scout Company. They attain the rank after completing their grueling training as an Aspirant and are given an Initiate as a tutor. Under the care of their Initiate superiors and acting as their squires, Black Templars Neophytes are deployed in Crusader Squads. Outside of battle, Neophytes have other duties such as caring for their Initiate's arms and armour, waiting upon their mentor during Chapter feasts, acting as second during honour duels, and standing long vigils while their Initiates engages in long prayer.

Towards the end of their tutelage, a Neophyte will be given a series of grueling trials by their Crusades Chaplains. If they are successful, they are then elevated to the rank of Initiate. Apothecaries oversee their final stages of transformation into a full Astartes, such as being augmented with the Black Carapace. Some of the newly ordained Initiates remain with their Crusader squad, while others are deployed to new roles.

Tactical Squads are the mainstay of the Space Marine Legions, highly versatile infantry units that can attack or defend at will, assault heavily fortified positions, take and hold strategic objectives – or simply slaughter the enemy – in almost any terrain or situation. All 18 Legions make heavy use of Tactical Squads in different ways – it is by the fighting power of thousands of superhuman warriors such as these, armed with deadly bolters and armoured for battle in the harshest of war zones, that the Imperium has beat a bloody path across the galaxy at the head of the Great Crusade.

Those of the Destroyer Cult are Necrons who have descended into apparent madness and are considered untrustworthy and dangerous by their own kind. They are agents of annihilation whose sole reason for existence is centred around an unshakable yearning to cleanse the universe of life. Unlike most other Necrons, those of the Destroyer Cult do not wish to reverse biotransference and regain their organic forms; instead they have heavily modified themselves to better kill their foes. What impels them to join the Cult is unknown but some suspect a subconscious imperative programmed into their command protocols - possibly by the C'tan.

Such is their hatred of life that members of the Destroyer Cult hold that they will relentlessly scour a planet's organisms down to the microscopic level. This includes plants, bacteria and even oceans, which they will boil with their weaponry. Even if it takes decades, Destroyers will never cease in their purge. They even welcome their own deaths, for they themselves are amongst the living and in the end will seek total oblivion.