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"That which is unknown and unseen always commands the greatest fear."

Dictatus Culexus, maxim of the Culexus Temple

The Culexus Temple is one of the most sinister and feared orders of the Officio Assassinorum and its Assassins have been described by Aeldari Warlocks as nothing short of the embodiments 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 Culexian 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.

The Assassins of this particular temple are not chosen because of their innate savagery, cunning or combat skills. First and foremost, potential candidates are chosen to be Culexus Assassins because they are born with an extremely rare human genetic mutation called the Blank Gene -- which means they have no presence within the Warp like all other sentient beings, and thus no soul.

Even normal humans find the presence of a psychic Null extremely disturbing, but the effect is most pronounced on psykers, who find Pariahs genuinely terrifying, as though staring into a hole in the universe when they use their Witchsight.

It is hardly surprising that Pariahs 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 Pariahs lead simple, solitary existences, as far away from heavily populated areas as possible.

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.


A Culexus Temple Assassin

When the Sisters of Silence first captured and transported large numbers of Pariahs 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 Pariahs 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 Adepta's very existence.

This was unfortunate, for the Officio Assassinorum had been working in secret with the Magos Biologis and Genetors of the ancient 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 Pariah's 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 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 Culexus Assassins would become an important component of keeping that vow.

The Fortress of the Soulless

Most of the other ancient temples of the Assassinorum are granted a certain amount of autonomy, allowing the general day-to-day running, training and sometimes mission assignation to be taken care of by older, more experienced Lord Assassins.

However, the Culexus Temple is ruled directly by high-ranking officials of the Officio Assassinorum. The temple itself is located not upon Holy Terra, but within a fortified complex located on a dead moon, outside the range of the Astronomican in the far reaches of the galaxy.

This is the Fortress of the Soulless, an echoing, armour-clad fastness that lies always beneath a suffocating blanket of dread. All Pariahs and Culexus Assassins are kept within the fortress unless on active duty.

If any are ever allowed to leave, then it is always under a veil of secrecy and with the highest levels of security. It cannot be doubted that the Culexus Temple has proven itself of invaluable use to the Imperium on countless occasions. Even so, there are factions within the Imperium that would see every Pariah executed and the Culexus Temple utterly destroyed.


"That thing really is an unparalleled witch-killer; it fights with a ferocity I envy and a fervour that I admire. Still, it’s a pity how frequently I need to replace the Acolytes assigned to watch over it. You’d think one would have gotten used to the thing before going mad by now."

Inquisitor Havelock Blackheel

A Culexus Assassin using his innate abilities to slay a Chaos Space Marine

Pariahs can nullify psychic powers, and if they are in close quarters to their targets their very existence drains the strength from psykers. Culexus Assassins therefore specialise in psyker-hunting, most notably of Aeldari Warlocks and rogue human psykers. Culexus Assassins have also been shown to be useful at combating daemons, as daemons are entirely composed of psychic energy drawn from the Warp and given form in realspace only so long as they have a link to the Immaterium or possess a mortal body.

A Culexus Assassin carries no gun or hand-to-hand weapons, for he needs none and would be distracted by their use. Once on the battlefield the Assassin's chosen Custodian will release his hold over the Assassin. The large eye in the Assassin's Animus Speculum opens and only then does the full intensity of the Assassin's horrific anti-psyker capabilities flood the battlefield.

The Culexus Assassin attacks using his own innate abilities enhanced by years of training, mental exercises and arcane wargear. He slips through the battle lines and bodyguards, his negative aura muddling the minds of conventional troops, allowing him to close upon his targets.

Bolts of negative Warp energy blast the minds of enemy psykers and strip them of their powers before he moves in for the kill, sapping the very life-force from their bodies.


A Culexus Assassin utilises the Animus Speculum to slay his foes

  • Animus Speculum - A uniquely designed battle-helm, the Animus Speculum can either muffle or focus the Culexus' powers as required. Only once an Operative is in the field do they reverse its contra-psychic dampers, allowing the full terror of their null aura to billow forth. The helm is only partially effective even while active, as most people can barely stand to be in the same room with a Pariah. At the same time, the grotesque lens set into the helm's leering faceplate can harvest and focus psychic energy into a devastating beam. In this way, the Animus Speculum allows the Culexus to turn the foe's own sorcerous powers against them, with horrific results. The Animus fires bolts of negative psychic energy, and can drain nearby psykers of their connection to Warp energy to increase its own power. Each Culexus Assassin is accompanied by a Custodian, who operates the Animus Speculum and ensures that his charge remains under his control and does not arouse suspicion amongst the other allied Imperial forces fighting in the campaign.
  • Psyk-Out Grenades - Culexus Assassins also use the exotic Psyk-Out Grenades, a weapon used exclusively by the Culexus Temple and the Daemon Hunters of the Ordo Malleus. These potent weapons contain pressurised canisters of psi-refractive particles that billow forth in crackling clouds when the grenade explodes. This highly dangerous substance is only produced as a metabolic by-product of the Emperor's Golden Throne on Terra. The dust-like substance is heavily impregnated with negative psychic energy and is very rare. When some has been collected, the Imperium's finest armourers use the dust to make Psyk-out Grenades and Psycannon rounds. For most victims caught in the cloud collapse of these particles, all conscious thought is driven from their minds. The effect is far worse for psykers, however, their powers fractured and turned inwards to tear bloody gouges in their psyche.
  • Synskin Bodyglove - The synskin of Culexis Assassins incorporates a nodal layer called Etherium. This strange technology shifts the wearer out of phase with reality, making them appear ghost-like and insubstantial. With the Etherium activated, an Operative becomes a ghostly retinal after-image, flickering toward the foe as though projected upon a faulty pict-reel. When required, a Culexus can simply vanish altogether, prowling through the midst of their enemies and reappearing only when doing so will reap the greatest harvest of terror. This, combined with the Culexus Assassin's innate anti-psychic abilities, means that psychic attacks pass right through him as if he were invisible. Another important aspect of the Etherium is the Force Matrix, the numerous psychic conduits that run within it. The Force Matrix is made from a material similar to that used in Force Weapons. When psykers tap into the Warp, they are not always efficient in using all of the energy they can absorb: much excess psychic energy is simply left to dissipate into the surrounding space. The Force Matrix acts as a conductor, absorbing this excess Warp energy and providing the Culexus Assassin, who is unable to tap directly into the Warp, with a source of energy to enhance his abilities. The closer the Culexus Assassin gets to psykers, the more energy the Force Matrix will absorb.

Notable Culexus Assassins

  • Sire Culexus - The founder and first Director Primus of his clade, Sire Culexus was the namesake and founder of the organisation that eventually became the Culexus Temple. He is presumably the first of his kind, and possessed the Pariah Gene. He, along with the other founders of the various clades that eventually became the Assassin Temples, was present on Mount Vengeance. With his fellow clade leaders he swore a pact in the shadow of the Great Crusade, an oath that breathed life into the creation of the Officio Assassinorum. The newly created Assassin clades hunted down the enemies of the Emperor through stealth and subterfuge, establishing the fact that there was no safe place to hide in the galaxy from the Emperor's justice.
  • 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.


  • Assassinorum Executioner Force: Rulebook (7th Edition), pp. 30-31
  • Codex: Assassins (3rd Edition), pg. 5
  • Codex: Assassins (2nd Edition), pp. 20-23
  • Codex: Grey Knights (5th Edition), pg.52
  • Codex: Necrons (3rd Edition), pg. 8
  • Rogue Trader: The Navis Primer (RPG), pp. 116-117
  • Nemesis (Novel) by James Swallow


Officio Assassinorum Temples
Callidus Temple Culexus Temple Eversor Temple Maerorus Temple Vanus Temple Venenum Temple Vindicare Temple