"For the Emperor! For Redemption! For the Mantis Warriors!"
8th Founding (Mid-34th Millennium) (Allegedly)
Approximately 100 Astartes remain
Various worlds in the Endymion Cluster; Tranquility III (primary training world before the Badab War); now Fleet-based Chapter
Green and Gold
- "The winds of the desert care not whose bones they scour clean."
- — Endymion Cluster proverb
The Mantis Warriors, originally known as the Mantis Legion, are a Loyalist Space Marine Chapter believed to have been Founded as part of the 8th Founding in 598.M35, created to help relieve the White Scars in monitoring and countering the many threats harboured by the Maelstrom Warp Storm in the Ultima Segmentum. They eventually were ordered by the High Lords of Terra to become part of an alliance of three Space Marine Chapters known as the Maelstrom Warders that also included the Astral Claws and the Lamenters. The Mantis Warriors held guardianship over the stellar region of the Maelstrom Zone known as the Endymion Cluster that contained a large number of human-settled Feral and Feudal Worlds. When Chapter Master Lufgt Huron of the Astral Claws declared that the Badab Sector had seceded from the Imperium in response to demands by the High Lords of Terra that seemed to be unjust intrusions upon the traditional autonomy of the Adeptus Astartes, the Mantis Warriors joined with the Astral Claws and the other Maelstrom Warders Chapters to defend what they saw as their rightful prerogatives and their Emperor-given duty to protect the peoples of their Maelstrom Zone region as best they could. The Mantis Warriors, like the other Maelstrom Warders Chapters, did not know that Lufgt Huron, in his hubris, had fallen to the desires for power and the temptations of Chaos, and when the civil war known as the Badab War concluded, the Mantis Warriors sought and received the Emperor's forgiveness after the Inquisition determined that there was no Chaotic taint upon them. It was determined that the Mantis Warriors' actions had been driven by an honest mistake and the deceits of the man now known only as Huron Blackheart, Traitor to the Emperor and servant of the Ruinous Powers. The Chapter was stripped of its guardianship of the Endymion Cluster, which was handed over to the Carcharodons Chapter (may also be the Space Sharks), while the Mantis Warriors were charged with undertaking a Penitent Crusade for 100 standard years during which they could recruit no Neophytes to make up their losses. However, following the Chapter's participation in the defence of the strategically important world of Herodian IV from a Tyranid splinter Hive Fleet in the late 41st Millennium, the Inquisition ruled that the Chapter had paid its penance to the Emperor and could begin to recruit once more to replace its great losses.
Long renowned across the Segmentum Ultima for their cunning, the Mantis Warriors Chapter are certainly one of the most unsung defenders of the Imperium of Man. To those few who have heard of them outside of the Eastern Fringes of the galaxy, the Mantis Warriors are renowned for their skill at guerrilla warfare, and the devastating ambushes and sudden, large-scale assaults they are capable of unleashing upon their foes. Like many Chapters who are tasked with standing as the sentinels over far-flung frontiers, or to carry out vigils in those darker backwaters of the galaxy where the darkest threats lie in wait, the Mantis Warriors long stood alone, their autonomy seldom challenged and no other allies to come to their aid. This persistent solitude was to change in the year 587.M41, when by an edict of the High Lords of Terra, the Mantis Warriors and their charges within the Endymion Cluster were incorporated within the newly formed alliance of Space Marine Chapters known as the Maelstrom Warders. With this change in status came, for the first time, an alliance of long-standing with two powerful and very different Chapters in culture and outlook, the Astral Claws and the Lamenters. Unfortunately this was an alliance that would ultimately prove to be the foundation of the Mantis Warriors’ undoing.
As with many Astartes Chapters of obscure origin, much of the details pertaining to the Chapter's history and the early disposition of the Mantis Warriors have been lost to the official Imperial record. Such teachings and lore the Mantis Warriors themselves retain on the matter have become so intertwined with myth and dense allegory as to be almost useless in diving certain facts. The earliest extant record in Imperial archives likely to pertain to the Mantis Warriors can be found in the Libris Gloriana – a 777-volume treatise on the state of Imperial power commissioned for the ascension of High Lord Gogol after the Nova Terra Interregnum in 093.M36. The large accumulation of knowledge in the Libris Gloriana is that rarest of commodities—a comprehensive Imperial historical chronicle. But it is one that has been repeatedly suppressed and censored by Imperial authorities, and many doubt its veracity, fearing too many "revisions" have been made. Further difficulties in the text are raised by the particularly obscure dialect of High Gothic in which the treatise is written, which had been popular at the Terran court of the High Lords of that time. It mentions in bombastic terms a Chapter of the Adeptus Astartes, a “…warrior legion of the Manos of the 8th Founding (which would place its origins in the mid-34th Millennium) of “…the line of the great Khan, by his sons the Marauders.” The text goes on to praise their successes in combating the Traitors of the Eye of Terror, as well as crushing xenos threats, and speaks of them as operating far from home. The ancient text failed to name these Astartes' Chapter homeworld or state the star system in which it was to be found.
That this elder Chapter spoken of in the Libris Gloriana and the Mantis Warriors of the Badab War are one and the same seems likely as the Chapter’s own historical legends allude to a great calamity in their past against which they undertook a Crusade lasting many centuries. Most tellingly, the Mantis Warriors’ gene-seed does bear the genetic tags of the White Scars bloodline (the Marauders Chapter being a Second Founding White Scars Successor). This last piece of evidence is particularly compelling as owing to certain endemic biogenetic difficulties in its cultivation by the Adeptus Mechanicus, the White Scars’ gene-seed has historically been one of the rarest employed in the creation of Space Marine Chapters, with less than a tenth of currently operating Adeptus Astartes units owing their origins to the scions of Jaghatai Khan.
The first truly accurate historical records for the Mantis Warriors are only available from the year 455.M38 when the Magos Invilgia of the Mechanicus noted that they had received a gene-seed tithe from the Mantis Warriors. This evidence establishes the Chapter as already being based within the Endymion Cluster, while noting that the collection was long overdue owing to the hostile local conditions in that region (a remark that indicates that the Mechanicus had already conducted prior, more successful, tithes, though the records have been lost to posterity). This evidence, combined with several other clues such as the Chapter's presence in the myths of the indigenous peoples of the worlds of Lastratti and Hu, indicates that the Mantis Warriors were present in the Endymion Cluster as its guardians for at least the last 1000 standard years. The difficulty of determining the Mantis Warriors' history and origins should come as no surprise for a Chapter that seemed to value solitude and autonomy as much as these Astartes do. The Mantis Warriors' character was always a fundamentally aloof one, uninterested in what was happening in the wider Imperium save for when it intersected with their own affairs or the affairs of the regions of the Imperial frontier that were under their protection. In fact, in the days before they were ordered to become a part of the Maelstrom Warders by the High Lords of Terra, their only real contact with another Imperial organisation was with the secretive Deathwatch Chapter of the Inquisition's Ordo Xenos, to whom the Mantis Warriors provided many Astartes over the years and who had similar interests in containing and eliminating the myriad xenos threats in the Maelstrom Zone and the Golgothan Wastes.
During the Badab War, the Mantis Warriors sided with their fellow Maelstrom Warders, the Renegade Astral Claws and the Lamenters, as well as the Executioners Chapter which owed a boon to the Astral Claws, who each answered Lufgt Huron's call to defend what they viewed as the traditional autonomy and political prerogatives of the Adeptus Astartes from encroachment by the Administratum and the deeply distrusted Inquisition by seceding from the Imperium. The first recorded involvement by Loyalist Space Marines in the conflict against the Mantis Warriors came in 904.M41, after the Fire Hawks' starship Red Harbinger was attacked and captured by the Mantis Warriors. In 907.M41, as Badab was being besieged by the Loyalists, two Chapters were drafted to also investigate the worlds occupied by the Mantis Warriors and the Executioners. In 912.M41 the rebellion was defeated and the Astral Claws were nearly destroyed. The Mantis Warriors, who recognised that they had been duped by the Chaos-corrupted Lufgt Huron into aiding his rebellion against the Imperium and that they were not defending the traditional autonomy of the Adeptus Astartes as they had believed, were granted the Emperor's forgiveness for their part in the conflict, and sent on a 100-year-long Penitence Crusade. The Mantis Warriors' surviving Chapter Master, Khoisan Neotera, was stripped of his honour and armour, and imprisoned in the Imperial prison known as the Penitentiacon in isolation for the rest of his life. As part of this Penitent Crusade, the Mantis Warriors' guardianship of the Endymion Cluster was forfeited to the Carcharodons Chapter (possibly the same Chapter as the Space Sharks), who had taken part in the conflict on the Loyalist side and launched the final assault on the Mantis Warriors stronghold of Tranquility II. This meant that for the duration of the Crusade the Mantis Warriors were forbidden to recruit new Neophytes, and at the end of the 41st Millennium, they found themselves critically short of personnel due to heavy attrition. However, recent events on Herodian IV have allowed the Mantis Warriors to reclaim the Emperor's blessing and begin to recruit Neophytes once more. Yet, such redemption may come too late and whether the Chapter will survive or not over remains a real issue for the Mantis Warriors, who may yet find the name of their Chapter added to those in the Imperial Palace's Hallway of Heroes who have been destroyed while defending the Emperor's Realm.
Badab War Aftermath
Before the rebellion, the Mantis Warriors had an above-average induction rate into the Inquisition's Deathwatch, but since their disgrace only a handful of Mantis Warriors have been accepted. They are no longer banned from recruiting Neophytes by the Inquisition because of their actions in aiding the Deathwatch against the splinter Tyranid Hive Fleet incursion on the strategically-located world of Herodian IV, although the Chapter's size is still dangerously low as a result of the steep losses they incurred during that campaign. Many Mantis Warriors believe that their Chapter is cursed and many outside the Chapter still regard them as Traitors despite their official pardon. They have been described as "a Chapter on the edge of the law, teetering on the brink of oblivion and approaching the borders of extinction, fighting desperately to regain its place amongst the chosen. They were not outlaws or renegades, but they had no home in the Imperium of Man."
- Hunt for Kharfra the Antipath (330.M39) - The Cardinal Kharfra, who had been corrupted by Chaos and founded a secret Chaos Cult within the Adeptus Ministorum, was discovered when his attempt to assassinate the Ecclesiarch Nyber Vasille failed, leading to a decades-long flight from Imperial justice for Karfra the Antipath and his cultists even as they unleashed a wave of destruction across the Segmentum Solar as they went. It was the Mantis Warriors who would eventually run the blasphemous priest to ground. Using intelligence taken from Maelstrom pirates by their Librarians, the Mantis Warriors learned that the Antipath had taken up refuge among the Chaos Renegades of the Golgothan Wastes. Over the course of a 5-year-long man-hunt, the Mantis Warrior discovered Kharfra's stronghold in the pre-Imperial ruins on the Death World of Parasis. The Mantis Warriors infiltrated the hideous fungal rainforests that surrounded the stronghold and defeated a force of mutants and heretics five times their own size before capturing Kharfra himself, now a benighted Chaos mutant, in the sewers below the stronghold. The Antipath was turned over to the Inquisition's watch-hold on the world of Valsingam for judgment. For this action, the Mantis Warriors gained the great gratitude of the Ecclesiarchy.
- The Scourge of the Slave Lords (901.M40) - In the centuries directly before the High Lords of Terra ordered the creation of the Maelstrom Warders alliance to defend the region, attacks from the Chaotic renegades and xenos of the Maelstrom Zone reached their highest levels in 2000 standard years. Faced with such overwhelming numbers, the Mantis Warriors were forced to fight with both creative tactics and great intelligence, luring foes into ambushes where they could and always seeking to fight only when they possessed the advantage. While this worked with great acuity against Orks and Chaotic raiders, the Dark Eldar pirates known to the worlds they raided as the Slave Lords proved another matter. Vicious and sadistic beyond the imaginations of men, the Dark Eldar were beings of shadow and mist, far too mobile and elusive to be easily trapped even by the Mantis Warriors' penchant for guile. The Dark Eldar loved to prey on undefended worlds, carrying off thousands of weeping, frightened people to a fate worse than death in their Dark City of Commorragh within the labyrinthine extradimensional corridors of the Eldar Webway. The Slave Lords' favoured prey were undefended Imperial merchant convoys and isolated planetary outposts. After the deaths of 60 Mantis Warriors Astartes during a failed attempt to defend the Feudal World of Tranquility II's primary shrine-city from a Dark Eldar strike, the Chapter decided to devote all of its resources to the destruction of the Slave Lords. With the aid of their Librarians, famed for their skills in intrigue and misdirection, the Mantis Warriors hatched a costly plan to defeat the Slave Lords. They let word go out into the region that they would defend the desert world of Tranquility II with all the resources at their disposal and they posted extra Chapter Fleet vessels in the system and gathered most of the world's small population of a bout a million people into a single encampment defended by 2 Space Marine forces, one highly visible and the other concealed beneath the world's desert sands. When news reached the Mantis Warriors of Dark Eldar diversionary attacks upon the void mining colony of Sigard, the Chapter ordered its fleet to leave the Tranquility System for Sigard, leaving the world seemingly undefended. When the Dark Eldar predictably attacked Tranquility believing that the Mantis Warriors had taken their bait, the Space Marines made the hard choice to wait until the Dark Eldar were fully committed to the raid, killing or capturing hundreds of innocents before the Mantis Warriors sprang their trap. The hidden Mantis Warriors rose up from the desert sands to confront the foe at the same time that two Cobra-class Destroyers of the Chapter Fleet, buried months before, shook off their own blankets of sand and fired their torpedoes at point blank range at the Dark Eldar ships and skimmers above. The torpedoes' fusion warheads badly damaged the Slave Lords' lightly armoured vessels, which immediately fled the world, leaving their comrades on the ground to be slaughtered by the enraged Space Marines and the desert tribes of Tranquility. But the Mantis Warriors Chapter Fleet returned from Warpspace as the Dark Eldar vessels reached the outer system, having never left for Sigard and they destroyed what remained of the Slave Lords' fleet, forever ending this Dark Eldar Kabal's threat to the people of the Endymion Cluster.
- Badab War (901-912.M41) - At the start of the Badab War, the Mantis Warriors were slightly below full strength because of the raids they had launched against the xenos on the outer edges of the Maelstrom and the resulting damage their 4th Company had taken in battle against the Genestealers of Verkruz. The Chapter possessed about 800 Battle-Brothers, 60-80 Scout Marines, their corps of Servitors and Chapter bondsmen, as well as 1 Battle-Barge, 3 Strike Cruisers, 2 Vanguard Cruisers, 6 armed transports and at least 19 Escorts and Attack Craft. The Mantis Warriors' reason for entering the Badab War was simple: they valued their alliance with the other Maelstrom Warders highly and saw an attack on one of their number, even by the Imperium itself, as an attack on themselves. They had the dubious honour of becoming the first of the Secessionist forces to fire on their fellow Astartes when they attacked and captured the Fire Hawks Chapter's starship Red Harbinger in 904.M41 when it crossed into their territory and refused demands to be boarded. In 906.M41, tragedy befell the Mantis Warriors during the opening stages of the Badab War, when both Loyalists and Secessionist forces met under a flag of truce on the world of Grief. During the proceedings a deceitful Lufgt Huron and his Renegade Astral Claws Chapter launched a surprise attack against the Red Scorpions and both their Chapter Master Lord High Commander Verant Ortys and the Mantis Warriors' Chapter Master Yarvan Sartaq were slain during the melee. As the conflict progressed, the Mantis Warriors were involved with the Secessionist war effort on every level, fighting guerrilla campaigns against the numerically greater Loyalist forces and often employing hit-and-run tactics. The greatest of these ambushes was the one at the world of Bellerophon's Fall which shattered the Marines Errant Chapter. Soon after the discovery of the heretical intent of Lufgt Huron and his Chapter, Inquisitorial missions were despatched to the homes of the Mantis Warriors and the Executioners Chapters to examine them for any evidence of complicity in the heresy, as well as genetic tampering and moral deviance of any kind. The mission to the Endymion Cluster was denied access to the Mantis Warriors' hidden bases, but was provided with samples of the Mantis' gene-seed for testing, which proved ultimately to conform within expected tolerances but with some gene-dissonance detected. As the war continued, the Mantis Warriors' strength was severely depleted fighting the Loyalists during the Tranquility Campaign to defend the Tranquility System and the Desert World of Tranquility II in the Endymion Cluster and following the Loyalists' retaliatory firebombing of Sacristan. There is some evidence to suggest that the Chapter had grown to have misgivings about the course of the war and the true goals and allegiances of Lufgt Huron and the Astral Claws by 908.M41, but too much blood had been spilled by that time for the Chapter's pride to allow anything but a violent conclusion to be found to the conflict. This was an end that came when the Loyalists, spearheaded by the forces of the savage Carcharodons Chapter, directly assaulted Tranquility II and finally crushed the Mantis Warriors' resistance. Yet the Secessionist Chapter gave as good as it got and 300 Battle-Brothers managed to survive the conflict to face the Emperor's justice. One year after the destruction of Badab Primaris, in 913.M41, the remaining Secessionists from the Astral Claws, Executioners, Mantis Warriors and Lamenters Chapters were put on trial before a specially convened Consistorial Court of their peers in the Adeptus Astartes. The very existence of these Chapters was at stake. Despite the attempts of the Inquisitor Legate to have the matter placed fully under Inquisitorial remit, a conclave of five Space Marine Chapter Masters whose forces were not part of the conflict were convened in judgement in accordance with Astartes tradition. The Consistorial Court found all of those Chapters who had taken part in the Badab Secession guilty of breaking with both the Codex Astartes and the ancient covenant with the Emperor that it represented. The Mantis Warriors were found to have rebelled against the Imperium not out of treachery but because they were misguided and had been manipulated by the Tyrant of Badab unknowingly. In the wake of the Badab War, the Mantis Warriors were sentenced to undertake a 100-year-long Penitent Crusade against the Emperor's foes during which they could not recruit Neophytes to make good their losses. Their future survival would therefore be left in their own hands and subject to the grace and benevolence of the Emperor.
- Centius Campaign (Unknown Date.M41) - The entirety of the Mantis Warriors' Veteran 1st Company was deployed for the Imperial campaign on Centius.
- Battle of Herodian IV (999.M41) - The Mantis Warriors answered a distress call from the world of Herodian IV when it came under attack from a Tyranid splinter Hive Fleet. They managed to evacuate 270,000 people off-world but the 2nd Company was badly mauled defending an Adeptus Mechanicus station on the world prior to the arrival of a Deathwatch Kill-team and an Inquisitorial fleet, drawn to the world because of its strategic location along a Warp route deemed critical to support Imperial efforts to defend against a Chaotic attack from the Eye of Terror. Following the successful defence of the Herodian System from the Tyranids the Inquisition determined that the Mantis Warriors' actions had restored the Emperor's blessing to them and they were allowed to begin to recruit Neophytes to replace their losses once more.
Unlike the progenitors the White Scars, the Mantis Warriors Chapter's deployment and organisation conforms closely to the tenets of the Codex Astartes and adheres to the Codex's prescribed numbers and types of companies, command structures, types of officers and other common elements of standard Space Marine Chapter structure. In practice however, due to the Chapter's history of isolation from the rest of the Imperium and lack of advanced technological resources, the Mantis Warriors have often had to fight under-strength, particularly in terms of the use of heavy vehicles like Predators and Land Raiders, of which they possess very few. The almost continuous slow attrition of their forces has made it necessary to operate with less than a full complement of Battle-Brothers. This has led the Mantis Warriors over time to concentrate their resources and limited capacity on wargear which they can best support. This suits their style of warfare which is heavily dependent upon guerilla attacks, hit-and-run tactics and misdirection. At the point in their history when they were at their lowest ebb they were still able to field a considerable fleet of Thunderhawk gunships and other Attack Craft to ensure their mobility in battle.
The Mantis Warriors have formed a specialized fighting unit within the Chapter, named the "Praying Mantidae," a cadre of warriors tasked with tracking down the Renegade Astral Claws (now called the Red Corsairs) that led the Mantis Warriors astray. These elite units are given additional training compared to "normal" Astartes. They are recognisable by the snake-like tattoos covering their body, extending high up on their necks. Mantis Warriors Battle-Brothers who are Veterans of the Tranquility Campaign that ended the Badab War are formed into Sniper Squads known as "Tranquility Sniper Squads". These Space Marines are known widely across the Imperium for their use of the Sniper Rifle and their yellow and black tiger-striped armour which was originally used as camouflage in Tranquility II's desert environments, but is now a mark of distinction.
Chapter Combat Doctrine
The Mantis Warriors' native character traits are further honed and enhanced when they become full Battle-Brothers through decades of combat experience in the field and the ferocity inherent in their progenitors' gene-seed. Unlike their White Scars forebears, their savage hearts are tempered by a streak of dark mysticism. The Mantis Warriors' focused power as a Chapter is like that of a sudden squall that comes and goes without warning, leaving only devastation in its wake. As noted, they are masters of guerilla warfare and the hit-and-run attack and will always seek to avoid combat through misdirection or guile until they have attained the maximum tactical advantage before unleashing the full fury of their assault.
The Endymion Cluster
The Endymion Cluster, the stellar region given to the Mantis Warriors to guard as one of the Malestrom Warders, was a region of Imperial space composed of 20 planets (6 of which were of major importance) that lay to the direct galactic east of Terra in the dangerous but resource-rich Maelstrom Zone of the Ultima Segmentum. The Cluster was surrounded on all sides by unsettled wilderness space and had never proven to be politically or economically coherent enough to be accepted as a fully-organised Imperial Sector since almost all of the human-settled planets within the Cluster were pre-industrial Feral and Feudal Worlds. The Endymion Cluster was located at an impressively dangerous astrographical position, with the horrors of the Maelstrom Warp rift behind it and the xenos-infested Golgothan Wastes between it and the Imperium's core worlds. Because of the Cluster's proximity to the Maelstrom, it possessed few reliable Warp routes in or out of the Cluster and what routes did exist were often plagued by Warp Storms or daemonic and xenos attacks. The Mantis Warriors served as the guardians of the Cluster, having protected its people for thousands of years, though rather than establishing their fortress-monastery on a single world, they preferred instead to found a clutch of small bastions and watch-holds across the entire region, many of them cleverly hidden to better maximise the Chapter's penchant for guerilla assaults and hit-and-run attacks.
However, the largest and most important base for the Mantis Warriors within the Cluster was a region of the Death World of Tranquility III that the Chapter named the Valley of the Nine Winds. This base was primarily used as a training ground for the Chapter's Neophytes, most of whom were recruited from among the peoples of the Endymion Cluster, particularly the desert world of Tranquility II, and full Initiates. The Chapter's control over the Endymion Cluster has been vital not only to the protection of the people of these planets but has also provided an excellent forward operating area for the Chapter, which is tasked with cleansing the Golgothan Wastes and the Maelstrom itself of the vicious daemonic and xenos threats which are far more dangerous than the odd Ork pirate or human corsair. For their part, the people of the Cluster's mostly primitive Feral and Feudal Worlds believe the Mantis Warriors to be the embodied spirits of warrior insects sent by the God-Emperor to protect them, and their loyalty to the Chapter runs bone-deep because of the countless times these Astartes saved the people of the Cluster from the literal legions of hell, as well as the reality that most of the Mantis Warriors were recruited from their own tribes and cities. It was these people who during the Badab War would side so faithfully with their ancient protectors and kin, and they would pay a terrible price in blood when the Loyalists unleashed their final assault on the Mantis Warriors in the Tranquility Campaign.
In character with their basic aloofness and desire for autonomy, the Battle-Brothers of the Mantis Warriors have an uncommon streak of individualism and self-reliance, for each one is born a survivor, a killer from the shadows, and the inheritor of a warrior lineage that descends from one of the Endymion Cluster's savage death world tribes or warring feudal states.
Each Mantis Warrior maintains their own wargear with a singular reverence, to a higher degree than most other Space Marine Chapters. Individual weapons and suits of Power Armour are handed down from generation to generation. Every custodian will in turn add their own embellishments to such an extent that each weapon and suit of Power Armour becomes a treasured and storied relic in its own right. This level of individualism is further evidenced by a high degree of customisation in insignia, kill markings and other form of personal adornment. This includes phophetic sigils and warding prayers engraved onto their armour or written on purity seals.
In the aftermath of the Badab War, one prevailing emotion has hung over the Chapter even after the end of their Penitent Crusade. Shame. There is still a feeling of shock and disbelief about how they allowed themselves to be blinded by their former Astral Claws allies and stray from the light of the Emperor, and they feel undeserving of forgiveness. To them, their rebellion was a crime that can never be fully atoned for, and their quest for redemption will never be at an end so long as their Chapter still exists.
The gene-seed of the Mantis Warriors has developed a flaw or mutation over the millennia as the Preomnor gene-seed implant does not function properly. As such, when a Mantis Warrior sets himself into a certain frame of mind, the Prenomor gland secretes a potent neuro-toxin that permanently changes the Astartes' physiology; the Space Marine is overcome by a feeling of the need for forgiveness for his many sins and shortcomings and a dramatically increased reverence for the Emperor. This neuro-toxin alters the Space Marine's sense of space and time, increasing his neurological reaction rate to that only achieved in near-precognitive states by most psykers; it also increases his already superhuman strength to a great extent. To a mortal it would seem that the Astartes is simply stepping aside before anything happens. Unfortunately, this marvelous gift comes at a price: the physiological change is irreversible and the Astartes' sight becomes tunnelized to the point of no longer being able to notice anything in his field of view that is not a target or a foe. The Mantis Warriors call this state of mind the "Battle-haze". Each Mantis Warriors' company has a unit of Battle-Brothers who have given their all to the Emperor and in acts of such faith have entered the "Battle-haze". These units are called "Mantis Religiosa." The Battle-Brother who discovered this genetic flaw was called Maetrus, a Captain, who after organizing the "Praying Mantidae" subsequently fell into the "Battle-haze" whilst battling a company of Astral Claws in the wake of the Badab War after that Chapter went Renegade.
All the Space Marines in this Chapter appear to have green eyes and long black hair, undoubtedly a phenotypic response to the Chapter's White Scars-derived gene-seed. The "Praying Mantidae" are recognisable by the snake-like tattoos that cover their body, extending high up on their necks.
Notable Mantis Warriors
- Khoisan Neotera - Former Chapter Master of the Mantis Warriors during the Badab War who replaced Yarvan Sartaq after 906.M41 until the end of the conflict; he was permanently imprisoned by the Inquisition for his role in the Chapter's rebellion in the Imperial prison Penitentiacon in isolation for the rest of his life. During the trial, he stood motionless for seven days and spoke only four words: "I seek no mercy".
- Yarvan Sartaq - Former Chapter Master of the Mantis Warriors who was slain in 906.M41 during the opening stages of the Badab War. While both Loyalists and Secessionist forces were under a flag of truce on the world of Grief, the deceitful Lufgt Huron and his Renegade Astral Claws Chapter launched a surprise attack against the Red Scorpions and both Chapter Masters Ortys and Sartaq were slain during the melee.
- Ahazra Redth, The Dust Prophet - Chief Librarian of the Chapter and one of the greatest Librarians in the Chapter's history, as well as the de facto Chapter Master of the Mantis Warriors during the final days of the Badab War. He is believed to have been killed during the Chapter's defence of Tranquility II from the final Loyalist assault, though his body was never found.
- Shaidan - Librarian
- Aegir - Chaplain
- Audin - Captain
- Maetrus - Maetrus was the Captain of the Mantis Warriors' 2nd Company. Maetrus was the intrepid and pious commander who first realised that Lufgt Huron had been tainted by Chaos and turned the guns of his Strike Cruiser, the Tortured Soul, against the Mantis Warriors' former allies the Astral Claws during the Loyalists' final assault on Badab Primaris. When Huron's fleeing cruiser punched through the Exorcists' blockade, Maetrus turned his ship in pursuit and charged into the Maelstrom with guns blazing in Huron's wake. His fate and that of his ship remains unknown.
- Treomar - Sergeant, 1st Assault Squad, 2nd Company.
- Kruidan - Sergeant (Assault Squad)
- Ruinus - Sergeant (Devastator Squad)
- Shaidan - Librarian
- Soron - Sergeant (Assault Squad)
The Mantis Warriors' Chapter fleet once consisted of 1 Battle-Barge, 3 Strike Cruisers, 2 Vanguard Cruisers, 6 armed transports and at least 19 Escorts and Attack Craft. Following the Tranquility Campaign that ended the Badab War for the Chapter, much of this fleet had been destroyed. The vessels that can be confirmed as remaining to the Mantis Warriors include the:
- Endless Redemption (Battle Barge)
- Penitent Quest (Strike Cruiser)
- Sword of Contrition (Strike Cruiser)
- Tortured Soul (Strike Cruiser) - The Tortured Soul was the flagship of the 2nd Company
The Chapter colour scheme was originally green and yellow, but has changed to shining green with gold edging. Mantis Warriors Sniper Units are known to have used yellow armour with black markings similar to three claw marks during the Tranquility Campaign of the Badab War.
The Chapter badge has been recorded to be both a flaming mantis claw in the past and a mantis head at present.
- Imperial Armour Volume Two - Space Marines and Forces of the Inquisition, p. 19
- Imperial Armour Volume Nine - The Badab War - Part One, pp. 9, 14, 17, 23, 28, 34, 41-42, 50, 61
- Imperial Armour Volume Ten - The Badab War - Part Two, pp. 9-10, 14, 18-19, 56-61, 64-73, 174
- Deathwatch (Novel Series) by C.S. Goto
- Legends of the Space Marines (Anthology), "The Trial of the Mantis Warriors" by C.S. Goto, pp. 377-427
- Warhammer 40,000: Compendium, "The Badab War", pp. 33-35
- Warrior Brood (Novel) by C.S. Goto, pp. 7-37
- White Dwarf 101 (US), "Index Astartes: From The Imperial History Archive - The Badab War: The uniforms and history of the Badab Uprising" (1988) by Rick Priestley, pp. 71-73