Warhammer 40k Wiki
Warhammer 40k Wiki

"To assume the shape of the accursed and deliver death from the purity within you - that is to be Callidus."

— Dictatus Callidus

The all-female Assassins of the Officio Assassinorum's Callidus Temple are the most subtle of the Imperium of Man's secret operatives, specialising in deceit and the use of artful deception to accomplish their objectives, usually assisted in their bloody tasks by the shape-changing Polymorphine drug.

The Callidus Temple's devotion to cunning and subtlety is often used on those missions where overt interference by the Imperium in a situation would upset the intricate balance of power maintained by the High Lords of Terra.

A Callidus Assassin is the ultimate weapon against those over-ambitious Imperial officials that would make a mockery of the Emperor of Mankind's justice whilst appearing to do no wrong. Those Imperial or planetary officials that use diplomacy, bribes and corruption to further their positions play a dangerous game within the corridors of powers.


A Callidus Temple Assassin.

Like all of the other temples of the Officio Assassinorum, the Callidus Temple was originally founded on Terra in the late 30th Millennium as the Callidus Clade during the Great Crusade at the direction of the first Grand Master of Assassins, Malcador the Sigillite. Malcador and the six men and women who would serve as the first Directors Primus of the Officio Assassinorum's founding clades had all sworn an oath at Mount Vengeance to eliminate the enemies of the Emperor of Mankind by any means necessary.

One of these Directors Primus, whose identities were all kept hidden, even from each other, was known as Sire Callidus and she was the founder of what became the Callidus Temple. The headquarters or temple of the Callidus Clade was established somewhere on Terra, where it is still located today.

Later, during the Horus Heresy, the Callidus Clade joined with the other five clades to assemble an unprecedented Execution Force of Officio Assassins intended to slay the renegade Warmaster Horus and bring an early end to the terrible civil war of the Heresy. This effort failed, though the Callidus Temple went on to prove a powerful instrument of Imperial policy in later millennia.


A Callidus Assassin armed with C'tan Phase Sword and Neural Shredder.

The vast majority of missions undertaken by Callidus Assassins involve infiltrating a Chaos Cult or other heretical organisation in order to kill its leader along with the other key members of the cult. Once the leadership of such a group has been removed, it is easier for the Imperium's regular armed forces to eliminate the cultists, without having to resort to extreme measures such as an Exterminatus order.

However, on less frequent occasions Callidus Assassins are called upon to undertake more exotic assassinations, requiring the use of both Polymorphine and surgical cybernetic implants to allow them to assume the form of a wider range of humanoids.

Although they are not typically fielded with a larger army on the field of battle, Callidus Assassins can be deployed behind enemy lines in order to infiltrate facilities such as bases or encampments and take out enemy leaders or key personnel. This is usually achieved by the assassin killing an isolated patrol or enemy unit and then assuming the form of one of those slain through the use of Polymorphine (also acquiring the armour and wargear of the deceased to complete the disguise).

Callidus Assassins are the most secretive and least understood of the Officio Assassins, as their usefulness would greatly diminish if their capabilities were more widely known. They are usually tasked with their missions on the order of the High Lords of Terra at the request of the Inquisition, especially the Ordo Hereticus, although as stated above, less frequent missions from the other Ordos are also undertaken.

To achieve the exacting tasks assigned to it, the Callidus Temple specialises in the use and development of the shape-altering drug Polymorphine to enable its Assassins to undergo dramatic physical changes, altering their appearance to assume the features of any humanoid (of whatever gender). This then enables the Assassin to infiltrate organisations or enemy bases and eliminate their assigned target with little opposition. The Callidus Temple is highly skilled in such deceptions, and often its work is not detected until the Assassin has already made a clean getaway.

The Callidus Assassins usually impersonate someone in a close position to, or holding influence with, the target. For example, a trusted advisor to a Chaos Lord, or the nursemaid to a child prophecised to cause much pain to the Imperium.

All of the Assassins of the Callidus Temple are trained in the use of Polymorphine. With this specialised drug alone a Callidus Assassin may masquerade as any human being she may choose, from a beautiful young woman to a crippled old man. However, in addition, the Medicus Adepts of the Imperium have developed a range of surgical implants to allow Callidus Assassins to mimic members of alien races, like the Orks and Aeldari.

These implants consist of flex-cartilage and hardened synthskin, similar to that used in the Black Carapace gene-seed organ of the Space Marines. When the Assassin is in their normal form these implants lie dormant under their flesh and within their bones. It is only when Polymorphine is injected that these implants react to the stimulants within the drug and transform into genetically encoded shapes that allow the Assassin to restructure their body into the grotesque and hunched form of an Ork, or the lithe and graceful form of an Aeldari.

Callidus Assassins can impersonate members of humanoid alien species, including the Kroot, Orks and, in at least one legendary case, a Genestealer Hybrid. The implants are often permanent, and restrict the Assassin solely to impersonations of that species. It should be noted that more humanoid species like the Eldar, Dark Eldar, and by inference most likely the Tau can be mimicked without implants through the sole use of Polymorphine.

Over the centuries, the Directors Primus of the Callidus Temple have learnt that the female body and psyche is better able to implement these changes, and by and large female Callidus novitiates make better chameleons than men. As such, almost all Callidus Assassins are actually women, regardless of who they are trying to impersonate.

Combat Abilities

Callidus Assassins undergo many Terran years of rigorous training to use Polymorphine and become one of the living weapons of the Callidus Temple. As part of its Assassins' training, the Callidus Temple practises innumerable ancient and secret martial arts. These arts train the Assassin in many deadly forms of armed and unarmed combat, against which even a battle-trained foe would be hard-pressed to find a suitable defence.

A Callidus Assassin must move among the enemy as one of them, so the choice of weaponry is always limited and in some cases the Assassin may be forced to fight with their bare hands. Even so, a Callidus Assassin is just as deadly unarmed as when carrying the lethal but easily concealed weaponry preferred by their Temple.

Combat Deployment

On the battlefield, Callidus Assassins are dropped behind enemy lines, where they use their cunning and skill at deception and stealth to infiltrate the enemy army. Usually this is done by eliminating certain individuals and taking their place.

By disguising themselves with the recently deceased's armour and wargear and using Polymorphine to change the shape of their body and face, the Callidus Assassin can assume the identity of almost anyone in the enemy force. Using this technique, the Callidus Assassin can get close to enemy commanders or powerful psykers, influencing their strategy and finally killing them when the opportunity arises.


Callidus Assassin wearing her specialist wargear

The weapons of Callidus Assassins are predominantly close combat or melee weapons, as their deception and infiltration skills and the use of Polymorphine enables them to get very close to their targets before they need to strike. This is assisted by weapons that are small and easily concealed and Digital Weapons are often preferred by these Assassins. Every Callidus Assassin is also a master of multiple forms of unarmed combat and many can kill with a single strike. The following are the most common weapons utilised by the Callidus Temple:

  • C'tan Phase Sword - If the Callidus Assassins have a signature weapon, then it is the C'tan Phase Sword, a "living metal" weapon made of the material known as necrodermis that was first created by the Necrons and which can be concealed easily. The blade of the Phase Sword is unusual in its ability to phase in and out of realspace by molecular realignment. It is capable of bypassing any protection, even energy shielding. This weapon is the product of excavations conducted millennia ago by the Adeptus Mechanicus on Mars which uncovered numerous artefacts of extremely advanced alien technology, but of their makers, the enigmatic C'tan and their Necron servants, there was no evidence. Each Callidus' phase sword is optimised to reflect their favoured combat stance and personal strengths, but they all take the form of an elongated punch-dagger. This weapon was used by the famed Callidus Assassin Jaramshaela in the attempted assassination of the heretical Imperial Planetary Governor Takis. This attempt failed because the governor was actually the C'tan known as the Deceiver in one of its myriad disguises.
  • Poison Blades - In sealed pockets across their synskin bodygloves, many Callidus Operatives keep an array of envenomed needles, each several inches long and wickedly sharp. The toxins on these miniature blades are enough to drop a full-grown Ogryn in seconds, and a Callidus is an expert at slamming them point-first through eye-slits, armour joints and other weak spots to ensure their victim's swift demise.
  • Neural Shredder - A Neural Shredder is a vicious and shockingly effective weapon against living targets. Though short ranged, the weapon projects a cone of psionic disruption that tears apart a victims' neural pathways. Armour is no protection against his hideous attack, even the mightiest foes dropping to their knees, spasming violently as liquidish brain-matter froths from their eyes, ears and mouths. This strange weapon's origin is unknown, although some speculate that it is but one of a range of psychic weapons developed by the Adeptus Astra Telepathica.
  • Synskin Bodyglove - Most Callidus Assassins enter combat wearing special stealth suits that enhance their abilities to avoid detection by most forms of passive sensors. These synskin bodygloves have several sealed pockets across it, where an array of concealed weapons and other items are stored.
  • Death Card - The death card is a flourish peculiar to some Callidus assassins, a surprisingly effective tool of terror. They will often place these psychoplas wafers on the corpses of those they have slain, slipped between the stiff dead fingers or gritted teeth of their victims. When touched by living flesh, the cards flicker to life. They project a hololith of the victim's face in their moment of death, complete with a looped recording of their agonised screams.

Notable Callidus Assassins

  • Siress Callidus - The founder and first Director Primus of her clade, Siress Callidus was the namesake and founder of the Callidus Temple. She, along with the other founders of the various Assassin clades that would eventually evolve into the current Assassin Temples, was present on Mount Vengeance. She and her fellows 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 clades hunted down the enemies of the Emperor through stealth and subterfuge, establishing the fact that there was no safe place in the galaxy to hide from the Emperor's justice.
  • Koyne - Koyne was a Callidus Assassin during the Great Crusade and opening days of the Horus Heresy. Koyne was a Shade of Clade Callidus ranked as an Epsilon-dan, the senior-most rank of the order. Having been a shape-changer for most of his/her life, Koyne often stayed in the form necessary for the completion of the mission and eventually had forgotten his/her original gender. Koyne was dispatched with the first ever Imperial Execution Force 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.
  • M'Shen - M'Shen was the infamous Callidus Assassin who successfully assassinated Konrad Curze, the Night Haunter, the murderous and unstable Primarch of the Night Lords Traitor Legion on the "Carrion World" of Tsagualsa. Despite Night Haunter's formidable powers of psychic foresight which forewarned him of the assassination attempt, he took no precautions to defend himself. It is believed M'Shen was allowed to infiltrate the Primarch's palace, as the Assassin encountered no guards between herself and the Night Haunter's throne room. When confronted by the Callidus Assassin's presence, the Primarch allowed himself to be killed to vindicate his decisions to destroy his homeworld of Nostramo and to rebel against the Emperor and because while he believed his actions had been right, he knew they also damned him. She is known as the only mortal who successfully killed a Primarch. M'Shen's death had been foreseen by Night Haunter's precognitive visions. He knew that although his Legion would allow her to escape, his heir apparent as the leader of the VIII Legion, Talos Valcoran (known as the Soul Hunter) and then the entirety of the Legion, would disobey his final orders to leave his killer alone and pursue the Assassin in the name of vengeance. As he had foreseen, M'Shen was pursued relentlessly by Talos across the galaxy. She eventually met a grisly fate at the hands of the former Night Lords Apothecary, who disemboweled her and tore her body to pieces. Despite her death, the video-recorder built into her vambraces somehow managed to reach Terra, containing the recorded enigmatic final words and imagery of the assassination of the Night Haunter.
  • Meh'Lindi - Meh'Lindi was a Callidus Assassin who was active in the late 38th and early 39th Millennium. Though the Callidus Temple has record of an Assassin with that name, they will not or cannot corroborate any more specific details. She was recruited from an unnamed Feral World and was particularly susceptible to Polymorphine, the shape-shifting drug used by the temple's Assassins. She was also known for her intelligence and fierceness. She was the subject of a unique experiment in the Temple's history, as she was implanted with genetically engineered organs and glands that allowed her to rapidly assume the identity and appearance of a Tyranid Genestealer hybrid which allowed her to infiltrate Genestealer cults and destroy them from within. This experiment, however, made it unable for her to assume any other transformation that that of the genestealer form. She later found herself serving in the retinue of the Inquisitor Jaq Draco. Meh'Lindi was known to make use of Jokaero-built Digital Weapons. Much later, Meh'Lindi and Jaq Draco's retinue, would make their way to the desert world of Darvash III, to track down the former Callidus Director Secundus, Tarik Ziz, and force him to reverse her surgery so that once again, Meh'Lindi would be able to assume any form with the use of polymorphine. Meh'lindi was ultimately killed in the Eldar Webway by a female Phoenix Lord. Meh'lindi was the Inquisitor Jaq Draco's lover, and he became obsessed with her "resurrection" which he thought possible thanks to the peculiar temporal properties of the Webway, specifically the existence of the Crossroads of No Time.
  • Mother Gullet - Legends tell of a daring and hideous crime perpetrated by a Callidus Assasin against a Planetary Governor who though himself strong enough to defy Imperial rule. The governor doted on his infant son, and had him guarded night and day to prevent his kidnapping to be used against him as a hostage. According to the tale, a Callidus Assassin disguised herself as the child's nanny, and so gained access to the princeling. Employing the shape-changing powers of polymorphine, the resourceful Assassin swallowed the child like a python, and carried it away past the guards in her belly. The Planetary Governor soon capitulated to Imperial authority.
  • Militzia Scarvelli - Militzia Scarvelli was a petite but fearsome Callidus Assissin, who in in the guise of a Gretchin slave-creature. Just as Oilguzla launches his Deff Dread horde at the Space Marines protecting Hive Imperator, Scarvelli recovers her phase sword from its hiding place in a nearby stack of scrap metal and attacks. Though it takes her almost a full minute to do so, she hacks the Big Mek into fist-sized chunks before overloading his force-field generator and bringing the stomping advance of the Deff Dread mobs to a grinding halt.
  • Syndalla - Syndalla is a fanatically devoted servant of the Emperor and the Inquisition. The sole survivor of Kalistradi’s retinue, Syndalla is a skilled Throne Agent and Assassin of the Callidus Temple. When the Genestealer uprising on the world of Avalos began, the rebels assassinated most of the PDF officers, leaving the guardsmen in chaos. Syndalla was present on this world during this time in the company of Inquisitor Kalistradi. Before the Inquisitor left to deal with the Genestealer nest, she told Syndalla to use her polymorphine to assume the guise of a PDF officer and hold the regiment together until she could return. Through Syndalla's efforts, she was able to keep the soldiers in ordered and maintain discipline while fighting against the rioters, while still waiting for word from her lord. When no word came, she kept up her guise hoping the Inquisitor's call for help was received. Syndalla would later aid a Deathwatch Kill-team that landed on Avalos in response to the Inquisitor's request for aid.
  • Tziz Jarek - Tziz Jarek was an infamous rogue Callidus Assassin who was active during the Wars of Vindication, which took place shortly after the death of the Renegade High Lord Goge Vandire during the Age of Apostasy's Reign of Blood in the early 36th Millennium. Vandire had managed to corrupt many within the Officio Assassinorum, just as he had bribed and blackmailed his way through the other Imperial Adepta. Foremost amongst Vandire's agents was Tziz Jarek. Using polymorphine, Jarek had assassinated the true Grand Master of the Officio Assassinorum and assumed his identity. However, unbeknownst to Jarek, the Grand Master had expected such a plot and had a decoy Assassin take his place in his chambers. As such, Jarek had not killed the true Grand Master, who secretly mustered those still loyal to him and the Emperor to fight against this usurper. A heinous battle raged within the Imperial Palace itself amongst the various factions of Assassins as they brought their terrible skills to the war. Ancient arsenals of the Officio Assassinorum were opened and terrifying weapons, long banned by the Senatorum Imperialis, were brought to bear by the Assassins on both sides against one another. In the end, the true Grand Master assassinated Jarek and disappeared into a self-imposed exile. After the conclusion of the Wars of Vindication, the hidden order of the Inquisition known as the Ordo Sicarius was set up to police the activities of the Officio Assassinoruum. The various Temples were split up and scattered to separate locations throughout the galaxy to ensure that if one should fall to xenos influence, daemonancy or heresy, others would remain untainted. Other rules were also put into place to ensure that no single individual could abuse wielding the power of the Officio Assassinorum for their own ambitions.
  • U'var - U'var was a Callidus Assassin who played an instrumental role in ending the Siege of Tullok in 872.M40. For fifty years the renegade Planetary Governor Urlos Grador had defied the lmperium from behind the fractal encergy shield of his grand palace, the shifting force walls seemingly impervious to attack. Finally, the Callidus Assassin U'var managed to infiltrate Tullok's sub-strata generatorium and interrupt power to the shields for a few short seconds. In this briefest moment, a single squad of Archangels Terminator' of the Blood Angels Chapter's elite 1st Company teleported into Grador's palace and brought the siege to an end in an hour of brutal Imperial vengeance.
  • Asaid Virenus - An infamous rogue Callidus Assassin, Asaid Virenus grew up in the Underhive of Perseus Hive on Olympas. Found by an Inquisitor at the age of twelve, she was given over to the Officio Assassinorum for testing to see if she was a suitable candidate for the Callidus Temple. She passed the physical tests easily, and her intelligence was clearly superior to most of the Imperium's inhabitants. There were doubts over her loyalty, but the masters of the Temple believed that through years of arduous training this could be overcome. Asaid continued to be rebellious and selfish, and at the age of seventeen it was likely that she would be quietly killed, considered unsuitable for further training. Though she had perfected many of the skills required of the Callidus, and had even begun to successfully use the shape-altering drug Polymorphine, her dubious motives had become too much of a worry for the leader of the Callidus Temple. Her tale would have ended there had she not fallen under the care of the Thorian Inquisitor Dahwrin who intended to use Asaid in a secret experiment involving the development of a new drug known as Hyperpolymorphine that was intended to artificially create a vessel for the rebirth of the Emperor-Incarnate. Surviving the experimental sessions, her own ruthless determination allowed her to master the side effects of the Hyperpolymorphine. Using the powers granted to her by the effects of the experimental drug, Asaid managed to escape. She now survives as a freelance Assassin, working for Imperial Commanders with political ambitions and has even worked alongside xenos and subversive Chaos Cults if the pay is right. Her dependence on certain stabilising elixirs has forced Asaid to raid Adeptus Mechanicus facilities in order to acquire sufficient drugs to preserve her life. These raids have provided a trail to her whereabouts for her main adversary, the Inquisitor Lord Antigonus Balorodin, to track her whereabouts. Balorodin's concern is not only for the acts of murder and mayhem that Asaid commits, but also the tacit threat her existence poses to the Imperium at large. While Asaid lives, anti-Imperial forces could capture her and learn many of the secrets of the Callidus Temple and the Inquisition. Should knowledge of how to manufacture and use Polymorphine be learned by the Emperor's enemies, it could cause untold damage, while the location of any Assassin Temple's outposts is a closely guarded secret.


  • Assassinorum Executioner Force: Rulebook (7th Edition), pp. 26-27
  • Blood Angels Painting Guide - Sons of Sanguinius, pg. 6
  • Codex: Assassins (3rd Edition), pp. 3, 6
  • Codex: Assassins (2nd Edition), pp. 12-14
  • Dataslate: Officio Assassinorum (6th Edition)
  • Deathwatch: Final Sanction (RPG), pg. 27
  • Index Astartes II, "Bringers of Darkness - The Night Lords Space Marine Legion"
  • Inquisitor: The Thorians (Background Book) by Gav Thorpe, pp. 16-17
  • Warhammer 40,000: Rogue Trader (1st Edition), pg. 170
  • Nemesis (Novel) by James Swallow


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