Strike Squads often form the vanguard of a Grey Knights strike force. Equipped with lighter armour than the main Terminator Squads, these veterans strike swiftly and surely, and are able to slip through gaps in the enemy line. At the onset of battle, a Grey Knights commander will invariably task one or more Strike Squads with the capture of vital locations and key objectives, deploying via fixed teleporter to ensure the rapid seizure of isolated or inaccessible locations. These Squads are essential – without their reconnaissance and preparation, the Terminator Squads would be a hammer swung blindly in the darkness.

FAQ: If a Grey Knight KT is reduced to one member, that one member is considered to be within range of himself for the purposes of Egregore Coordination and all equivilant proximity requirements.

Many vectoriums unleash heaving swarms of Poxwalkers to soften up and encircle their foes. The first the enemy knows of such an onslaught is the stink of diseased flesh upon the air, mingled with the agonised groans of countless plague-ridden mutants. Then they come - spilling from doorways and windows, boiling up from sewer outlets, trench networks and subterranean transit networks, crawling out of vehicle wrecks and rising from carrion heaps; thousands upon thousands of Poxwalkers converging on the foe at a stumbling yet relentless pace. Engulfed in a sea of grasping hands, biting maws and bloated flesh, even the finest strategies of the foe falter and fail. The enemy finds themselves forced into a battle for survival as they strive to fend off the Poxwalkers closing in from every side. It is at this point that the Death Guard themselves strike. Off balance, broken into desperate pockets and running low on ammunition, the foe has little hope of standing against this second, more punishing onslaught.

Hastarii are heavy Skitarii heavy infantry whose bodies have been modified to carry the destructive heavy firepower of much larger Adeptus Mechanicus machines.

Their modifications include having their right arms replaced with gyroscopically stabilized gun mounts that are wired into the hastarii's cortical circuits. This results in the heavy infantry having uncanny accuracy with their weapons. Hastarii Exterminators are anti-infantry specialists equipped vicious Eradication Casters, while the Hastarii Fusiliers wield Neutron Fusils to destroy enemy armour. They also have lighter weapons on shoulder mounts - Exterminators have an Arc Blaster while Fusiliers use a Phosphor Blaster.

However, because of their gun mounts, the Hastarii must wear advanced backpack generators to function, which are heavy and difficult to manufacture. Also, while Hastarii are highly effective in battle, they are complex and costly for the Adeptus Mechanicus to create. As a result of these drawbacks, the Hastarii variants are rarely deployed in battle, in order to avoid a wasteful loss.

Because of their skills, the Hastarii have become a vital element of the Skitarii's Macro-Clades and are heavily used by the Archmagos Terminus Thulia Ghuld.