- "To the righteous we bring hope. To the tainted we bring fire."
- — Castellan Garran Crowe
A Grey Knights Purifier is a member of a select order that stands apart from the other Battle-Brothers of the Grey Knights Space Marine Chapter. The Purifiers epitomise the Chapter's sanctity of purpose. Purifiers recruit only from those amongst their Battle-Brothers whose souls are considered to be utterly incorruptible and resistant to the temptations of the Warp -- even by the already exacting standards of the Grey Knights. So careful is the selection that there are seldom more than a few score Purifiers within the Chapter at any one time.
- "When the came, they brought the fires of the God-Emperor with them. Though I am blind, I know the light of the God-Emperor when I see it."
- — Astropath Von Shruk
Just as the Paladins embody the epitome of the Grey Knights’ martial prowess, so the Purifiers demonstrate the best of their strength of purpose and founding principles. Purifiers are selected not for their skill at arms nor the glory of their deeds, but based on the purity of their souls and their single-minded devotion to their sacred purpose. Only the most pure of heart and clear of purpose can hope to face the most powerful foes of the Warp. The Purifiers stand apart from the Chapter, a secretive order within a secretive order. They have the sacred duty to maintain the seals and bindings on the Chapter’s daemonic prisoners and deal with the worst the Warp has to offer. In battle, Purifiers can turn their purity into a weapon, channelling it with their psychic talents to create an ethereal fire which can literally burn away the souls of their foes and reduce a fully-manifested daemon to nothing but a memory in a few moments of blazing light and inhuman screams.
The Chambers of Purity lie deep below the Grey Knights' fortress-monastery on their Chapter homeworld of Titan in the Sol System, at the entrance to the ancient and shadowy vaults of Mount Anarch. This ensures that the Purifiers guard against the evil that slumbers therein. Only the Chapter's Grand Masters are permitted to enter these halls unbidden. This edict has proved something of a challenge to Grey Knights Neophytes over the centuries. Some return to the chambers above following a brutal beating to reinforce the lesson that the Purifiers trust not even their own Battle-Brothers where some secrets are concerned. Other intruders do not return at all, their fate a mystery. Purifiers are dour and taciturn, and their eyes burn with a black fire that borders on fanaticism. There is neither training regime nor set process by which a Grey Knight can join the ranks of the Purifiers. Membership in the Purifier Order is not granted through skill, valour or a tally of grim deeds soaked in blood. A Grey Knight can serve his Chapter with distinction for centuries without end, yet still this ultimate honour may well be denied him.
Purifiers recruit only from those amongst their Battle-Brothers whose souls are considered to be utterly incorruptible and resistant to the temptations of the Warp -- even by the exacting standards of the Grey Knights. So careful is the selection that there are seldom more than a few score Purifiers within the Chapter. Yet never has there been any thought of relaxing the restrictions on induction, lest the sanctity of the order be compromised. Fortunately, the limited numbers of Purifiers have never yet been too few for the task at hand. Whether this is due to some strange quirk of fate or the machinations of some higher power is impossible to say. Perhaps it is part of the natural order of things for there to exist a handful of unblemished warriors, whose purpose is to combat daemons in all their forms and to ensure that the fire of victory is never extinguished. This is perhaps scant comfort to the Purifiers, who inevitably form the Chapter's spearhead in the dark times of the late 41st Milllennium. But for the Purifiers, as for all Grey Knights, duty comes before personal survival.
- Aegis Power Armour
- Wrist-mounted Storm Bolter
- Nemesis Force Sword
- Frag Grenades and Krak Grenades
- Psyk-Out Grenades
- Liber Daemonica - The Liber Daemonica is an enduring symbol of a Grey Knight's devotion to his mission, and contains the cardinal tenets of lore culled from the dark knowledge caged within the Sanctum Sanctorum's walls. Every Grey Knight carries a copy of the Liber Daemonica in a Ceramite case on his breastplate. These gnarled tomes contain the Chapter's rites of battle and detail the traditional duties of every Grey Knights rank. The books themselves are also potent psychic talismans in their own right, with pages illuminated in silver and bound to a spine carved from the thigh bone of a martyred saint.
- Cleansing Flame - Purifiers can call on their purity, psychic gifts, and fanatical devotion to duty to create a nimbus of flame around themselves that burns all nearby enemies with white hot soul fire. When this power is manifested the Purifier bursts with white light and is momentarily surrounded by a corona of consecrated flame. The Purifiers then send forth the pure fire in their souls to consume their foes.
- Hammerhand - Focusing the raging power of their minds, Grey Knights can augment their already prodigious might. Even unarmed, such a warrior can crush flesh and bone -- given blade or warhammer there is little limit to what they can slay.
- Castellan Garran Crowe - Garran Crowe is a notable hero of the Grey Knights order known as the Purifiers. Crowe is both the leader and the Champion of this Grey Knights' elite order. Crowe is charged with the wardenship of the powerful artefact known as the Blade of Antwyr, a daemonic sword that continuously brings him into both physical and spiritual peril by tempting him with Chaotic promises of power or seeking to bind his will with black sorcery. Crowe must be forever on guard, for the sword's sibilant whispers echo endlessly through his mind, offering to lend its strength to his own in the pursuit of victory. Many men would embrace such a chance, gambling that their will would be strong enough to control the sword's bounty without becoming corrupted in return. Yet, no matter how dark the hour or desperate the battle, Crowe has never succumbed -- his thoughts and actions are his own. He is the guardian of the Blade, incorruptible and inviolable, and will remain so until the day of his death.
- Codex: Grey Knights (5th Edition), pp. 31, 42
- Dark Heresy: Daemon Hunter (RPG), pp. 126-127