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"The Daemon came for us on the bridge. Flesh and metal ran like water around it and the Daemon laughed. There was a moment when I was convinced I was going to die. In the next heartbeat, Danton stepped onto the bridge from the main lift. He stared at the Daemon and took a single step forward. That one step was like the world re-aligning itself, reality restored. The Daemon snarled...and then it stepped back."

—Helmsman Cathur of the Triumph of St. Drusus

The Sisters of Silence were the most notable Blanks employed by the Imperium of Man during the Great Crusade and the Horus Heresy.

A Blank, also known as an Untouchable, a psychic Null, and a Pariah, is a Human who possesses the rare mutation sometimes described as the "Pariah Gene" that makes them generate no psychic presence in the Immaterium, thus leaving them essentially soulless.

Known also as "Blacksouls" and "the Soulless," a Blank is a living anathema for all psykers, regardless of their species.

The minds of most sentient beings have a direct connection to the Warp that is actually what is called the soul in many cultures.

Psykers have especially strong connections to the Warp, and their souls thus appear as blazing brands to those who can see within the Immaterium, spiritual beacons which draw the hungry attention of Warp denizens.

Blanks are born with no connection to the Warp at all, their presence completely invisible within the Empyrean. In fact, the minds of Blanks can actually somehow sever the connection between the Warp and realspace within their local area.

The result is that a Blank dampens any psychic or Warp-related powers occurring within their aura's area of effect. A psyker standing within the Blank's range will find their powers weakened if not wholly nonfunctional.

The Blank themselves is immune to all direct psychic effects. However, a psyker could still attack a Blank indirectly by using their abilities to telekinetically launch a projectile at them.

A Blank is the direct antithesis of Chaos as he or she possesses no presence within the Warp. Blanks are completely immune to daemonic possession and spiritual corruption by the forces or agents of Chaos.

Blanks can also interfere with the Tyranid Hive Mind's ability to telepathically link Tyranid bioforms through its synapse organisms.

However, this interference is nowhere near as powerful as what their abilities do to beings composed of pure psychic energy such as entities native to the Warp like Daemons, who find the presence of Blanks painful, even to the point that they will be driven back into the Immaterium.

A Blank's proximity to someone who possesses even a modicum of psychic ability can also be quite painful or even lethal to the psyker, especially to psychically-sensitive beings such as the Aeldari.

Even ordinary, non-psychic individuals categorised as Level Sigma and below in psychic ability can be affected by a Blank's anti-psyker aura, as they radiate a sense of unnatural "wrongness" that makes all other living creatures extremely uncomfortable and uneasy in their presence.

People in the presence of an Untouchable will often harbour intensely hostile feelings towards the Blank for reasons that they cannot explain. As a result, most Pariahs do not live long as the feelings of hatred and distaste they generate among even non-psychic individuals means they have few friends and many enemies.

The Soulless are very rare in the galaxy since perhaps only one person on an entire world will be a carrier of the mutation in every Human generation.

It is believed by some in the Adeptus Mechanicus that the genetic complex of changes collectively sometimes called the "Pariah Gene" were deliberately engineered into the genomes of the ancestors of Mankind by the Necrons millions of standard years ago during the War in Heaven.

Blanks today are most often used by the Officio Assassinorum's Culexus Temple and as Acolytes by Inquisitors of the Ordo Hereticus who find them to be useful psychic shields and weapons against the witch and unsanctioned psykers.

The Ordo Malleus finds Blanks to be superb living weapons against Daemons.

Additionally, every member of the Sisters of Silence, the Imperium's most effective anti-psyker military force, is a Null. On the Psyker Scale commonly employed by the Adeptus Astra Telepathica, Blanks occupy the nethermost levels, from Phi-plus to the extraordinarily rare Omega-minus level.

While only Humanity is known to naturally produce Blanks, they have also come into being in certain alien races, such as the Solitaires of the Aeldari Harlequins, who have lost their own souls to Slaanesh through unspecified means.


A Culexus Temple Assassin utilises the Animus Speculum to slay his foes.

When the Sisters of Silence first captured and transported large numbers of Untouchables back to Terra during the Great Crusade, Humanity had its first disturbing revelation of the potency of these strange mutants.

As large groups of Pariahs were brought to Terra, they began to cast a shadow in the Warp, blocking out the Astronomican, the vital psychic beacon used to guide starships to the far reaches of the Imperium.

Other branches within the Imperium of Man, especially those that relied upon the abilities of psykers, were horrified by the existence of Pariahs.

Several members of the Council of Terra sought to have Pariahs outlawed outright like other dangerous mutants -- tasking the Sisters of Silence with the ruthless extermination of any more Blanks that were found just as they eliminated Renegade psykers who presented a threat to Humanity.

A number of members of the Council of Terra, including the Paternal Envoy of the Navis Nobilite, were pushing the Emperor of Mankind to issue an official decree to rid the Imperium of the "anti-psyker" mutants that threatened their Adeptas' very existence.

This was unfortunate, for the Officio Assassinorum had been working in secret with the Magos Biologis and Genetors of the Mechanicum on the order of Malcador the Sigillite, the Regent of Terra and the founder of the Officio as the first Grand Master of Assassins, to see if it was possible to harness the Blanks' strange abilities and use them to kill psykers.

Their work was almost complete; many years had been spent developing specialist wargear and training techniques, all of which was about to be ruined by a zealous political witch-hunt.

Fortunately, the Emperor never had to issue an official decree, for at Malcador the Sigillite's behest, the Mechanicum announced that it was ending the Pariah Project, making a great show of closing down its laboratories and executing many of the "specimens" it had tested there.

Satisfied that no further action was needed, the bureaucrats of the Council of Terra turned their attention to the more important matters at hand.

However, closer study of the fragmentary Imperial records from this time reveal that the number of executions did not match the number of Pariahs contained within the laboratories of the Mechanicum.

Working in collusion with the Officio Assassinorum, the Mechanicum spirited away the most promising Pariahs to a specially constructed fortress hidden on Terra, beyond the reach or knowledge of the more zealous branches of what eventually became the Adeptus Terra after the Horus Heresy.

It was there that the Culexus Temple, originally known as the Culexus Clade, was born in its modern form under the direction of its first Director Primus, the individual known only as Sire Culexus.

Culexus had sworn an oath alongside Malcador and the five other directors primus of the newborn Officio Assassinorum to defeat every enemy of the Emperor no matter where or how they sought to hide from Imperial justice. The Blanks of the Culexus Clade would become an important component of keeping that vow.


Silent Sisterhood

A Silent Sister of the Frost Spider Vigilator Cadre.

The most well-known example of the use of Blanks by the Imperium of Man was the existence of the mysterious all-female order of Witch Hunters known as the Sisters of Silence.

During the Great Crusade era in the late 30th and early 31st Millennium, their purpose was to hunt and kill rogue Human psykers whose activities presented a terrible danger to the people of the newborn Imperium.

Also known as the "Silent Sisterhood" and the "Witchseekers," they were the militant arm of the Astra Telepathica and were referred to internally within the records of the Council of Terra (predecessor to the Adeptus Terra and the Senatorum Imperialis) as the Departmento Investigates.

Along with the Legio Custodes, the Sisters of Silence had the right and duty to walk freely within the inner sanctum of the Imperial Vaults, the sovereign and sole domain of the Emperor and His Household at the behest and license of the Master of Mankind.

The Sisters of Silence's primary base of operations was the Somnus Citadel on Luna, the moon of Terra. These warrior-investigators were tasked with the apprehension of untrained psykers, often colloquially referred to on primitive Human worlds as "witches," whose abilities sometimes manifested in ways that could be very dangerous to their fellow Human beings, particularly if they became possessed hosts for the foul entities of the Warp.

The Sisters operated the Astra Telepathica's infamous Black Ships, which ranged the galaxy following behind the Great Crusade's expeditionary fleets in search of rogue psykers to capture or expunge, seeking to collect and carry them back to Terra where they would be tested and their eventual fate decided. Though few in number, the Sisters of Silence commanded great respect within the Imperium and most servants of the Emperor regarded them with some awe.

Few would willingly stand in their way or interfere with their activities and few indeed were those who were comfortable in their presence. It is hardly surprising that Blanks are often treated like outcasts or lepers in Imperial society, rejected by their parents and banished from their homeworld's local settlements.

Local superstitions on many worlds often warn about touching them, saying that to do so would bring bad luck. Resigned to their fate, many Blanks lead simple, solitary existences, as far away from heavily populated areas as possible.

Following the end of the Horus Heresy, Mankind had become superstitious and fearful of the unknown, and the Silent Sisterhood were cast out by a distrustful Imperium.

They disappeared from Imperial history for nearly 1,500 years, until the Imperium faced annihilation at the hands of the massive Ork WAAAGH! led by the Warboss known only as The Beast. The last vestiges of the Silent Sisterhood would play a key role in defeating this Ork WAAAGH!, thus diverting disaster.

Though officially disbanded after the Age of Apostasy in the 36th Millennium, many enclaves of the Silent Sisterhood still fight for the Imperial cause in the modern era, albeit in a more secretive and specialist capacity than before, and would eventually play an important role against Abaddon the Despoiler and the forces of Chaos during the closing years of the 41st Millennium.

Following the resurrection of the Primarch Roboute Guilliman during the 13th Black Crusade, the Sisters of Silence were reinstated formally as the Adeptus Astra Telepathica's Departmento Investigates and accompanied Guilliman on his Indomitus Crusade.

Culexus Temple

A Culexus Temple Assassin of the Officio Assassinorum.

Another well-known instance of Untouchables used by the Imperium are the Culexus Assassins of the Officio Assassinorum's Culexus Temple. The Assassins of this temple have been described by Aeldari Warlocks as being nothing short of the embodiment of pure evil.

Even amongst the upper echelons of the Officio Assassinorum this temple is always viewed with extreme caution. The reason for this is not because of the way that the Culexus Assassins carry out their operations, or the heinous methods of killing they employ. It is because of the very nature of the Culexus Assassins themselves.

This extremely rare genetic defect occurs for no known reason in less than one in a billion individuals.

All psykers and intrinsically psychic species like the Aeldari consider a being like a Culexus Assassin to be an absolute abomination. Even monstrosities such as a Tyranid Hive Tyrant can balk at the prospect of being permanently severed from their psychic abilities and the Hive Mind.

The Culexus Assassin causes absolute terror in all psykers -- which is why they are so useful to the Imperium.


All the Ordos of the Inquisition makes eager use of Blanks, as they are the most potent kind of anti-psyker tool there is. They are very useful in the fight against witches and Daemons and are sometimes used as Acolytes in the retinues of certain Inquisitors.

The Blank is typically made to follow their master around like a tourist, protecting his master from witchcraft and sorcery with his mere proximity.

Space Marines and Custodians

At the time of the Horus Heresy, there were no known records of any Pariahs serving within either the Legiones Astartes or Legio Custodes.

Some Imperial scholars have suggested that, for the Space Marines, this is due to the psychically-infused nature of the Astartes gene-seed, which could render it lethal if implanted in a subject carrying the Pariah Gene.

It is, however, possible for a Space Marine to be transformed into a Pariah after implantation, as is the case with the Ferrymen who serve the Grey Knights.

Ordo Sinister

During the Great Crusade and Horus Heresy eras, the Ordo Sinister exclusively employed Blanks as the commanders of its Psi-Titans.

Known as preceptor-intendants, these Blanks were equivalent to the Princeps used by the standard Titan Legions of the Collegia Titanica, but were also tasked with directing and focusing the powers of the psykers that were surgically bound into each Psi-Titan.

Astra Militarum

When identified within their ranks, Blanks have been utilised by the regiments of the Astra Militarum for dealing with rogue or xenos psykers, though they appear to be as rare within the Astra Militarum as they are elsewhere.


The Necrons utilize blackstone, also called noctilith, which is a unique substance that has Warp nullification effects when negatively "charged" that led many in the Imperium to dub it "Pariah Stone."

However blackstone doesn't just negate psychic powers or effects, it can also be used to amplify the powers of the Warp should it be "charged" in the right way.

Pariah Gene

The exact biological source which creates in a Human being the state of psychic Null, the so-called "Pariah Gene," has proven an elusive and ephemeral subject of study, and in testing no single "gene" at all.

Such attempts to exploit or isolate it when pursued by both the Imperial Archotechnologist Corps and the Mechanicum during the Great Crusade's early years courted disaster, and as a result the Emperor decreed a general moratorium upon the study of the biological basis of the psyker Null phenomena, affecting all but His own direct experimentation should He wish it.

What remains of those extant studies indicates that most attempts to synthesise, propagate or even weaponise the psychic Null were tragic failures or worse. Despite all this evidence, shadowed accounts of certain clades of the Officio Assassinorum and the dread and obscure Ordo Sinister also contain evidence of the Emperor's own "engineered" use of the psychic Null in warfare. To others however, the mystery of the Pariah Gene, if it truly exists, remains out of reach.

So many unanswered questions revolve around this most arcane and dangerous of topics. Foremost are those which centre around theories of how the Pariah Gene came about: was it perhaps the result of xenos tampering with the Human genome or some strange and terrible experiment of the Age of Technology?

Or, as the wildest theories state, is it some perverse evolutionary development of the Human species against the Warp-given cosmos itself? There is also the observation that no Space Marine, or Custodian Guard for that matter, has ever been recorded as being a psychic Null.

This factor weighs the evidence of some scholars that within the Space Marines' gene-seed itself is perhaps a shadow of the Emperor's own genetic material and a sliver of His own psychic power crucial to the process and success of the transition from mortal to Astartes. If this is the case, it would be wholly an anathema to the Pariah Gene and likely simply kill its implanted subject.

It can only be speculated that if even a single Legion of psychic Null Legiones Astartes had been possible, how very different history may have been -- just as without the involvement of the Sisters of Silence in the war and the Emperor's Webway Project, Horus' treachery may well have ended in triumph upon the broken throne of Terra.

True Blanks

While the term "Blank" is often ascribed to all who possess the anti-psychic mutation, true Blanks, also called "Untouchables," are those Humans who possess the Pariah Gene in its recessive form in their genetic code.

A Blank is often not aware of his powers and may not be able to control them even if he is, but the aura of negative psychic space he projects is highly disruptive to psychic powers. A psyker will find it difficult to impossible to affect the Blank and anyone in his general vicinity with his powers.

Blanks have a better chance than true Pariahs to live a peaceful life, for since their aura of "otherness" is weak, baseline Humans may simply pass it off as queerness and leave the Blank alone.

Blanks are often recruited as acolytes to serve as living shields against psychic attacks by Inquisitors and are forced to tag along wherever the Inquisitor goes.

Generous or pragmatic Inquisitors might even provide their Blank with combat training and some equipment to augment their living shield's survivability.


Pariahs, also known as "Blacksouls", "Psychic Nulls", or the "Soulless", are mutants in whom the Pariah Gene is dominant. They have no presence whatsoever in the Warp and thus no "soul."

Their aura of "otherness" is so powerful that a baseline Human finds it impossible to be in the Pariah's presence; and they are a living embodiment of the worst possible nightmare for any psychically-gifted being.

Unlike Blanks, true Pariahs can siphon off and thrive on the psychic energy of psykers, breaking the connection between the Warp and the Materium wherever they go, and their aura quickly proves fatal to psykers in its area of affect.

Pariahs are quite often killed at birth as mutants, for their "otherness" is very palpable.

Surprisingly, Pariahs have always been much sought-after by the Imperium, first organised in the all-female Sisters of Silence order, and now trained to become the much feared Culexus Assassins.

Notable Blanks and Pariahs

  • Ferik Jurgen - Jurgen was an Imperial Guardsman originally of the 12th Valhallan Field Artillery Regiment, who served as aide, driver and adjutant to Commissar Ciaphas Cain. Jurgen saved the life of his Commissar on more than one occasion thanks to his ability to dampen psychic powers.
  • Culexus Assassins - All Culexus Assassins are fully-fledged Pariahs, trained and equipped to the highest Imperial standard to become the bane of psykers across the galaxy.
  • Iota - Iota was a female member of the Culexus clade during the Great Crusade and Horus Heresy era. Iota was designated as a Protiphage, for she was not fully Human in the strictest sense; she was a clone, or as they were known in the Imperium, a replicae. Created by the Emperor's biologians, Iota was conceived from cells that had been combined in a test tube in a laboratory. As a Culexus Clade operative she was a being without a soul, closer to a xenos than her own kind. She was dispatched with the first ever Imperial Execution Force that was composed of Imperial Assassins from every clade, who were attempting to assassinate the Traitor Primarch Horus upon the world of Dagonet. Ultimately, their assassination attempt failed and all the Assassins were slain by the Traitors.
  • Necron Pariah Warriors - The Necrons harvest Human Pariahs and transform them into these cybernetic abominations to protect themselves from psychic activities.
  • "Spear", the Black Pariah - Within Imperial history, there has only been one known so-called "Black Pariah" to have ever existed. He was a former Imperial Assassin by the code-name of "Spear", who lived during the time of the Horus Heresy. Born as a Human Untouchable, he was captured by the Silent Sisterhood and brought to Terra, where Clade Culexus experimented upon and augmented him in an attempt to create a more powerful and deadly form of Culexus Assassin. It is not known whether these augmentations or his unnatural abilities made him a Black Pariah. Spear was eventually deemed too unstable and dangerous by his clade's masters to be left alive. He was placed in the care of the Sisters of Silence and was sent aboard one of their lone vessels, bound for the heart of a nearby sun. Unfortunately, this vessel was intercepted by a Renegade vessel carrying the Dark Apostle Erebus of the traitorous Word Bearers Legion. Boarding the Sisters' vessel, the Word Bearers killed all aboard, with the exception of Spear. Sensing the usefulness of such a unique specimen, Erebus found a new purpose for his captive. He forced Spear to undergo a painful and vile Chaos ritual, in which a minor Daemon from the Immaterium was bonded with the former assassin. This bonding created a highly dangerous apex predator -- a "counter-psyker" -- capable of redirecting a psyker's attack directly back upon them. In order to utilise this ability, the Black Pariah first had to obtain a sample of his target's blood. This was a necessary component that helped him synchronise with his target's psionic abilities in order to reflect their attacks. Two standard years later, following the events of the Drop Site Massacre on Istvaan V, Erebus tasked his deadly minion to assassinate the Emperor. Spear spent an inordinate amount of time in order to painstakingly reach his ultimate goal -- a document that possessed a minute drop of the Emperor of Mankind's precious blood. Spear obtained the document on the world of Dagonet, bringing him into direct conflict with an Imperial Execution Force composed of Imperial Assassins from every clade, who were attempting to assassinate the Traitor Primarch Horus. Though the mission was ultimately deemed a failure, resulting in the death of all its members, this confrontation resulted in the Black Pariah's destruction. Horus later chastised Erebus for his audacious plan to assassinate the Emperor, declaring that when the opportune moment finally dawned, it would be him -- and him alone -- who killed the Master of Mankind.
  • The Distaff - The Distaff was a group of Blanks created and utilised to hunt rogue psykers by the notorious Inquisitor Gregor Eisenhorn in the 41st Millennium and also seconded by him to other Inquisitors for particular investigations. The leader of this unique group of Untouchables was Alizabeth Bequin. The Distaff proved instrumental in the defeat of the Traitor Inquisitor Quixos, a formally venerated Radical Inquisitor of the Ordo Malleus who became tainted by Chaos. The Distaff was finally destroyed in 386.M41.


  • Codex: Assassins (3rd Edition)
  • Codex: Assassins (2nd Edition), pg. 10-12
  • Codex: Grey Knights (5th Edition), pg. 52
  • Codex: Necrons (3rd Edition), pg. 17
  • Horus Heresy: Collected Visions (Background Book) (Sisters of Silence)
  • The Horus Heresy - Book Seven: Inferno (Forge World Series) by Alan Bligh, pp. 123, 125, 127, 129-130, 136-137, 247
  • Flight of the Eisenstein (Novel) by James Swallow
  • Thousand Sons (Novel) by Graham McNeill
  • Nemesis (Novel) by James Swallow
  • Prospero Burns (Novel) by Dan Abnett
  • Tales of Heresy (Anthology), "The Voice" by James Swallow
  • Inquisitor Annual Exterminatus Part II
  • Rogue Trader: Navis Primer (RPG), pg. 84
  • Eisenhorn Trilogy (Novel Series) by Dan Abnett
    • Xenos (Novel) by Dan Abnett
  • Ravenor (Novel Series) by Dan Abnett
  • For The Emperor by Sandy Mitchell
  • Caves of Ice by Sandy Mitchell
  • The Traitor's Hand by Sandy Mitchell
  • Death or Glory by Sandy Mitchell
  • Ciaphas Cain: Hero of the Imperium by Sandy Mitchell
  • The Emperor's Gift (Novel) by Aaron Dembski-Bowden, Ch. 11
  • Warhammer 40,000: Forgebane (8th Edition Boxed Set), pp. 2-13
  • Honourbound (Novel) by Rachel Harrison