Lord Commander Eidolon of the Emperor's Children Legion during the Horus Heresy

Eidolon served as one of the eleven Lord Commanders of the Emperor's Children Legion during the Great Crusade and Horus Heresy eras. At one time, Lord Commander Eidolon was hailed as the exemplar of all that the Emperor's Children aspired to. He was elevated to Company Captain by the IIIrd Legion's Primarch Fulgrim himself, becoming the first Space Marine to lead an entire company within the Legion. He achieved such perfection that he went on to become the Legion's pre-eminent Lord Commander.

Eidolon was commonly regarded as the most proficient of all the Legion's Lord Commanders, having been a dedicated student of the art of warfare in all its aspects. If Eidolon had any imperfection, it was overconfidence, a characteristic that bore rotten fruit as it was twisted into overweening arrogance after the Legion's corruption by Chaos. In striving towards the perfection embodied by his Primarch, Lord Commander Eidolon submitted himself to the attentions of Chief Apothecary Fabius, receiving biological augmentations that allowed him to project a psycho-sonic dirge as formidable as any weapon.

The Lord Commander's native skill and his augmented powers were given full rein upon the bloody sands of Istvaan V, where he unleashed a cacophonous storm upon the Loyalists even as his perfect bladework cut them to crimson ribbons. Eventually Eidolon's arrogance angered his corrupted Primarch and he was decapitated by Fulgrim with the Chaos blade known as the Kinebrach Anathame after he dared to question why Fulgrim had ordered the IIIrd Legion to assault the relatively unimportant Adeptus Mechanicus world of Prismatica V.

Unsubstantiated rumours over the last ten millennia persists that Eidolon yet lives; responsible for hundreds, if not thousands of raids upon Imperial worlds. There is some evidence to suggest that Eidolon has served as a lieutenant to Abaddon the Despoiler, a consort to Queen Sylelle as well as a Chaos Champion of the Daemon Prince N'Kari.


Long ago, during the turbulent era known as the Age of Strife, Warp travel became impossible and all the worlds which humanity had claimed were cut off from one another, forced to fend for themselves without the support of their neighbours in other star systems. The Libram ex Dominar, one of the few surviving texts from this time, tells that Chemos was one such world, a mining colony dependent on interstellar trade for food. Following the end of Old Night the Emperor of Mankind first publicly revealed himself during a series of conflicts to reunite the disparate techno-barbarian nations of Terra, collectively known as the Unification Wars. Following their successful conclusion the Emperor began to forge the foundation of the Imperium of Man in the 30th Millennium. The Emperor began a massive scientific effort to create the Primarchs -- 20 genetically-engineered sons that would serve as the Emperor's generals and command the Emperor's forces during the Great Crusade to reunite the scattered human race beneath His leadership. Their genomes later served as the genetic template from which the Emperor crafted his 20 Space Marine Legions.

The Ruinous Powers of Chaos somehow manage to spirit the superhuman children away through the Warp, however, leaving them scattered across the galaxy. A massive localized Warp rift was created within the gene vaults of the Emperor's own palace, deep under the Himalazian (Himalayan) Mountains on Terra where the Primarchs were gestating. The gestation capsules containing the Emperor's unborn sons were scattered through the Warp to colony planets long since lost to Mankind. Each of the Primarchs somehow found themselves on ancient worlds of men, planets long since lost to the light of the greater universe beyond the stars. The infant Fulgrim, Primarch of the Emperor's Children Legion grew up upon the bleak, dying world of Chemos, a mining colony long fallen to decay and decline as Old Night claimed the domains of Mankind. Isolated from surrounding systems, the industry of Chemos had fallen silent, the mines replaced by the reclamation plants and vapour extraction facilities that kept the dwindling population from vanishing entirely. Within fifty years of his arrival on Chemos, Fulgrim had risen to become its leader, and it was his dream that the wonders of long lost ages might be rediscovered and rebuilt. However, it was only when the Emperor came to his world that the Primarch could begin to fully realise his vision. By that time, it was not simply his home world that Fulgrim desired to see elevated to glory, but the entirety of Mankind.

When Fulgrim was introduced to the IIIrd Legion, the Astartes Legion that shared his genetic inheritance, he found not a resplendent host as did so many of his brothers, but a mere 200 Battle-Brothers. An accident had befallen the nascent Legion early in the development of its gene-stock, setting it far behind its fellows. Eidolon was one of these original surviving Astartes of the IIIrd Legion who had originally been born on Terra. Thus, it was necessary that Fulgrim and his warriors be integrated into the ranks of another Legion until such time as their numbers were sufficiently restored for them to take to battle on their own. The Legion to which Fulgrim and his warriors were assigned was the Luna Wolves, the Legion of Horus, and Fulgrim could not have had a better companion at whose side to master the arts of warfare.

From the earliest days of its service to the Great Crusade, the nascent IIIrd Legion was recognised for its drive to attain perfection in all its deeds. It was in recognition of this drive that the Emperor granted the warriors of the IIIrd Legion the right to bear the Imperial Aquila upon their chest armour, a unique honour at that time. In recognition that the Emperor was the very pinnacle of the perfection Fulgrim aspired to, the IIIrd Legion was named the Emperor's Children, a title it would retain even after the calamitous events of the Horus Heresy.

Cleansing of Laeran

Shortly after the beginning of their own Crusade, the Emperor`s Children encountered a hitherto-unknown alien race upon the xenos planet called Laeran, officially designated as Twenty-Eight Three, being the third world the 28th Expedition had brought to Imperial Compliance. Unbeknownst to the IIIrd Legion, the Laer were corrupted xenos worshipers of the Chaos God of Pleasure, Slaanesh. Though the Ocean World of Laeran would be of immeasurable value to the crusade of the Emperor, its alien inhabitants did not wish to share what blind fortune had blessed them with. They had refused to see the manifest destiny that guided Mankind through the stars and had made it abundantly clear that they held the Imperium in nothing but contempt. The IIIrd Legion's advance had been rebuffed with violence, and honour demanded they answer in kind. Fulgrim ordered his Lord Commanders to attack immediately, beginning a war that the Council of Terra predicted would last at least a decade.

During the ensuing campaign, the IIIrd Legion's Chief Apothecary Fabius discovered upon examining some of the corpses of the Laer that the serpentine creatures had been engaged in extensive genetic engineering to perfect their species, creating a multitude of different castes who were genetically designed to best serve their intended function in Laer society. Bringing his findings to his Primarch, Fabius explained that the Laer were not so dissimilar to the Emperor's Children in their approaches to perfection. He put forward the hypothesis that what the Emperor had made was incredible, but what if it was but the first step on a longer road? Fabius suggested that if they were to look upon their own flesh they could find new ways to improve upon it and bring it closer to perfection. The Apothecary may very well have signed his death warrant by speaking so frankly, but the possibilities that might be opened up were worth any risk. To attempt to unlock the secrets of the Emperor’s work in creating the Astartes would be the greatest undertaking of his life. Fulgrim inquired if Fabius truly believed that he could enhance the gene-seed of the Astartes. The Apothecary admitted that he didn't know for certain, but he believed that they had to at least try, for by doing so they would move closer to perfection -- and only by imperfection would the Emperor's Children fail the Emperor. The Primarch agreed with the Apothecary's proposition and gave Fabius free leave to do what needed to be done.

With the end of the war on Laeran, the steady stream of wounded and dead to the Apothecarion slowed, leaving Fabius more time to devote to his researches. To ensure the secrecy his experiments demanded, he had relocated to a little-used research facility aboard the Andronius, a Strike Cruiser under the authority of Lord Commander Eidolon. Its facilities had been basic at first, but with Eidolon's blessing, he had gathered a bewildering array of specialist equipment. Eidolon had taken a personal interest in Fabius's work, though he disapproved of his methods. Fulgrim had told the Lord Commander of the scale of what he was to attempt, for his work would enhance the physiology of the Astartes. Eidolon informed the Apothecary that when he returned from his more laborious duties, Fabius would begin his experimentation on him. Through the Apothecary's genetic enhancements, the Lord Commander hoped to become Fabius's greatest success, faster, and more deadly then ever before. He wished to become the indispensable right hand of the Primarch.


Lord Commander Eidolon departed the 28th Expeditionary Fleet to take part in the reinforcement of the Blood Angels Legion upon the world of Urisarach, which was officially designated in Imperial records as One-Forty-Twenty, as the twentieth world to be brought into Imperial Compliance by the 140th Expeditionary Fleet. This world was discovered by that fleet, which was commanded by the Blood Angels Legion's Captain Khitas Frome. Unable to translate the warnings from the orbiting Interex satellite beacons that warned approaching starships to stay away from Urisarach since it was a prison world of the dangerous sentient xenos species known as the Megarachnids, the Blood Angels Captain Khitas Frome ordered the fleet's entire contingent of three companies of Space Marines to begin landing operations to investigate and bring the planet into Imperial Compliance. Due to the extreme atmospheric turbulence, all of the Blood Angels' shuttles attempting to land on the planet became scattered and were thrown far off-course which left the Imperial landing parties isolated from each other. The atmosphere also affected Vox (radio) communications and made it difficult for the Imperial forces to coordinate their movements. Ground teams soon started sending garbled transmissions to the fleet's ships in orbit, reporting that the planet was inhabited by extremely hostile xenos.

As the reports continued, the large arachnid-like xenos were described as too numerous and formidable to defeat without reinforcements. Not long afterwards, the Blood Angels made urgent distress calls requesting immediate reinforcements and extraction. The last transmission received by the fleet came from Captain Khitas Frome himself, who noted through clenched teeth, "This. World. Is. Murder." The name stuck and became the Imperium's informal appellation for Urisarach thereafter. A company of the Emperor's Children Legion under the command of Lord Commander Eidolon eventually arrived in response to the Blood Angels' distress calls. They made the same mistakes the Blood Angels had made, and had their landing parties scattered by the planet's powerful atmospheric disturbances. While the company took heavy casualties, one landing party led by Captain Saul Tarvitz discovered a large rock-like structure that resembled a dead tree. This "tree" had the bodies of several Blood Angels Space Marines impaled on its many branches with flying variants of the Megarachnids feasting upon the bodies. After destroying the structure, the sky above where the "tree" had been suddenly began to clear of the violent storms that had afflicted the Imperial forces from the beginning. Captain Tarvitz realised that these structures were actually artificial weather control devices that were responsible for Murder's heavy atmospheric turbulence.

The Megarachnids immediately went about rebuilding the "tree" and sent hundreds of warriors to slaughter the last few Emperor's Children who remained. There had been little honour in the initial drop to the planet’s surface, amid the death and frantic nature of the combat against the loathsomely quick Megarachnid warriors. It had been brutal, intense and bloody work, and many good warriors had met their end beneath Murder's raging, bruised skies. Thanks to Eidolon’s mistakes, there had been precious little glory won until the Luna Wolves had arrived and brought their strength to bear. Just as the Emperor's Children force were about to be overwhelmed, a relief force of newly-arrived Luna Wolves Astartes from the Warmaster Horus's own 63rd Expeditionary Fleet began to land through the breach in the atmosphere. The Megarachnids were scattered and a full-scale assault on the hostile xenos of Murder began in earnest after Eiodolon butted heads with Tarik Torgaddon when the latter accused him of causing needless death for his own glory. Ten companies of Luna Wolves, the remnants of the Emperor's Children, tens of thousands of Imperial Army soldiers, and several Legio Mortis Titans proceeded to level entire swathes of the grass stalk forests and destroy every one of the "trees" they encountered, which steadily eroded Murder's atmospheric barrier. Horus, who was commanding the Imperial assault from his flagship in orbit, was very pleased with the progress being made. Some consideration had been paid to initiating a withdrawal from Murder now that a proper landing zone was available to allow an easy extraction of the troops, when an unexpected visitor suddenly arrived.

The Primarch Sanguinius had come to the world to inspect the dead of his original Blood Angels landing force that had been wiped out early in the campaign. Adding five of his companies of Blood Angels to the Imperial invasion force, Sanguinius and his forces fought alongside the Warmaster against the aliens. Thousands of Megarachnids poured out of the forests and canyons of Murder in an endless wave. Despite never retreating from the Imperial assault, the Megarachnids only continued to lose ground. By the sixth month of the campaign it seemed the Megarachnids would soon face extinction when the fleet deployed by the Interex arrived in-system to determine who had assaulted the Megarachnids' reservation world. Finding contact with the highly-advanced humans of the Interex to be a more pressing issue that needed to be dealt with, the Warmaster ended the campaign against the xenos of Murder.


After another successful Compliance action was conducted on the Imperial world designated Twenty-Eight Four, Eidolon underwent elective augmentative surgery under the knife of Chief Apothecary Fabius. He implanted a modified tracheal implant that bonded with the Lord Commander's vocal chords, allowing him to produce a nerve paralysing shriek similar to that employed by certain warrior breeds of the Laer.

When the Apothecary explained the nature of the new organ implanted into the Lord Commander's throat, Eidolon was outraged that Bile would implant xenos filth within him. Enraged, he ordered the Apothecary to halt the surgery and release him from the medicae table. But Fabius refused the Lord Commander's orders, for Fulgrim himself had authorised his work and Eidolon had insisted that the Apothecary work on him upon his return. The Lord Commander would later make use of this new ability whilst leading his 1st Company in concert with the Death Guard Battle-Captain Nathaniel Garro and his 7th Company against traitorous forces on Istvaan Extremis, the outermost planet within the Istvaan System. Whilst fighting against a powerful Slaaneshi mutant known as a Warsinger, Garro was laid low. It was then that Eidolon took hold of the situation and employed his newly acquired abilities, destroying the Warsinger with a devastating sonic shriek. In light of this, Eidolon may potentially be considered as one of the first Noise Marines.

Horus Heresy

Istvaan III Atrocity

Eidolon's descent into the clutches of Chaos only deepened during the Battle of Istvaan III after Horus betrayed the Loyalists within his own Traitor Legions to cleanse his troops of any who remained beholden to the will of the Emperor of Mankind. The Warmaster ordered the Loyalists' contingents from the the Sons of Horus, World Eaters, Death Guard and the Emperor's Children to begin the planetary assault. While these forces were busy laying siege to Choral City, the seat of Istvaan III's government, the Warmaster callously ordered the orbital bombardment of the planet. Fortunately, the Loyalist Captain Saul Tarvitz of the Emperor's Children was aboard the Strike Cruiser Andronius and had discovered the plot to wipe out the Loyalist Astartes of the Traitor Legions. He was able, with help from Battle-Captain Nathaniel Garro of the Death Guard who was in command of the Death Guard Frigate Eisenstein, to reach the surface of Istvaan III despite pursuit and warn the Loyalist Space Marines he could find of all four Legions of their impending doom. Those that heard or passed on Tarvitz's warning took shelter before the virus-bombs struck.

The civilian population of Istvaan III received no such protection: 12 billion people died almost at once as the lethal flesh-dissolving virus called the Life-Eater carried by the bombs infected every living thing on the planet. In the aftermath of their deaths, a global fire storm raged as all of the dissolved organic matter caught fire. The Primarch of the World Eaters, Angron, realising that the virus-bombs had not been fully effective at eliminating all the Loyalists, flew into a rage and hurled himself at the planet at the head of 50 companies of World Eaters Traitor Marines. Discarding tactics and strategy, the World Eaters Traitors worked themselves into a frenzy of mindless butchery fed by their growing allegiance to the Blood God Khorne. Horus was furious with Angron for delaying his plans, but Horus sought to turn the delay into a victory and was obliged to reinforce Angron with troops from the Sons of Horus, the Death Guard, and the Emperor's Children, as the massive pall of ash hanging over the world after the Life-Eater attack precluded an immediate orbital bombardment.

On Istvaan III, the remaining Loyalists, under the command of Captains Tarvitz, Garviel Loken and Tarik Torgaddon, another Loyalist member of the Sons of Horus, fought bravely against their own traitorous brethren. Yet, despite some early successes that delayed Horus' plans for three full solar months while the battle on Istvaan III played out and he waited for the atmosphere to clear, their cause was ultimately doomed by their lack of air support and Titan firepower. The few remaining Loyalists of the Emperor's Children Legion fought bravely on Istvaan III, led by Captains Saul Tarvitz and Solomon Demeter. To prove his worth and loyalty to Lord Commander Eidolon of the Emperor's Children -- and thus to his Primarch, Fulgrim -- Captain Lucius of the 13th Company of the Emperor's Children, the future Champion of Slaanesh known as Lucius the Eternal, turned against the Loyalists that he had fought beside because of his prior friendship with Saul Tarvitz.

Given open access to the Loyalists' eastern flank, hundreds of Traitor Emperor's Children Legionaries, led by Lord Commander Eidolon, streamed into the Precentor's Palace from the east, on a tide of fire and blood. They fell upon the wounded first, Eidolon himself butchering those who lay waiting for an Apothecary's ministrations, taking particular relish in killing the Loyalist Emperor's Children he found there. The warriors of his Chapter swarmed through the palace around him, the defenders discovering to their horror that their flank had somehow been turned and that more and more of the Traitors were pouring into the palace. Within moments, the last battle had begun. The Loyalists turned from their defences and faced the Emperor's Children. Assault Marines' Jump Packs gunned them across ruined domes to crash into Eidolon's assault units. Heavy weapons troopers and Scout snipers amongst the ruined battlements shot down into the enemy, swapping tremendous volleys of fire across the shattered domes. It was a battle without lines or direction as the fighting spilled into the heart of the Precentor's Palace. Each Astartes became an army of his own as all order broke down and every warrior fought alone against the enemies that surrounded him.

As the main Traitor attack column was storming the broken holdfast of the Precentor's Palace, in the northern and southern sectors further assaults were taking place to break the back of the Loyalist resistance and hunt down the scattered survivors in the ruins. In the subsequent final orbital bombardment of the planet by the Warmaster's fleet, it brought the resistance of the Loyalists to its brutal, bloody conclusion. Horus ordered the guns of the Vengeful Spirit turned once more upon the carcass of the Choral City, not with viral weapons but conventional warheads, and pulverised its ruins flat before leaving Istvaan III a corpse-cinder in the wake of the Traitors' progress. The bombardment of the planet triggered tectonic convulsions: the earth trembled, fissures opened in the ground, and buildings toppled even as Legion brothers fought one another under the collapsing roofs. Across Istvaan III, in ever-shrinking circles of defiance, the last Loyalists of the four Traitor Legions died under the blades of warriors who had once been their brothers. However, Eidolon had over-extended his lines and the Traitors themselves were outflanked in a final inspired attack by Tarvitz. Horus withdrew his troops after this, and completed the destruction of the Choral City with an orbital bombardment. This spelled the end for the few remaining loyalists. But they died knowing they had taken a blood price from those who had betrayed them.

Drop Site Massacre

Final victory for the Traitors on Istvaan III had been bought with many lives, but in its wake the Traitor Legions were tempered in the crucible of combat to do what must be done to seize control of the Imperium. The process had been long and bloody, but the Warmaster's army was ready and eager to fight its brothers, where the lackeys of the Emperor would find their readiness to strike down their kith and kin untested. Such mercy would be their undoing, Horus promised. Horus would strike a vicious blow against the Imperium and the False Emperor -- a blow that would resonate down through the millennia for all time. The Warmaster still had to make preparations for the inevitable response of the Emperor, which was likely to arrive more quickly than anticipated and the Traitors needed to be prepared for it. Fulgrim was tasked to take a detail of Emperor's Children to the ruins of the alien fortresses that existed on Istvaan V and prepare that world for the final phase of the Istvaan operation. Fulgrim supervised the vast teams of Dark Mechanicus earthmovers as they shifted the black sand of Istvaan V and formed a vast network of earthworks, trenches, bunkers and redoubts that stretched along the ridge of the Urgall Plateau. Laagers of anti-aircraft batteries were set up in the shadow of the walls, and mighty orbital torpedoes on mobile launch vehicles hid in the warrens of an ancient alien fortress. If the Emperor's Legions wanted to destroy the Traitors, they were going to have to come down to the surface of Istvaan V to do so, as no obital bombardment would be powerful enough to dislodge the defenders or crack their resolve.

Overcome with mind-numbing rage at their brothers' treachery, Ferrus Manus and his Iron Hands Legion gratefully received the Emperor's orders through his brother Rogal Dorn. In response to Horus' betrayal of the Loyalist Astartes in the Sons of Horus, Emperor's Children, World Eaters and Death Guard Legions at Istvaan III, the Primarch of the Imperial Fists Legion, Rogal Dorn, on the direction of the Emperor who had learned of Horus' actions from the Loyalist survivors aboard the Eisenstein, ordered seven Loyalist Space Marine Legions to Horus' base on the world of Istvaan V to put down the Warmaster's rebellion. They would attack in two waves and fall under the supreme command of the Iron Hands' Primarch Ferrus Manus. The Legions comprising the first wave were the Iron Hands, Salamanders, and the Raven Guard. The Legions comprising the second wave, who would arrive at Istvaan V after the first wave, were the Alpha Legion, Night Lords, Iron Warriors, and a large contingent of Word Bearers that their Primarch Lorgar had stationed in the star system. Unknown to Dorn and Ferrus Manus, the Night Lords, Alpha Legion, Iron Warriors and Word Bearers had all turned from their service to the Emperor and pledged their loyalty to Horus, and been instructed to keep their new allegiance to Chaos a secret.

Caught between two armies, the first wave of the Loyalist forces were systematically massacred. Unrelenting gunfire from the Iron Warriors at the drop-site, and the resurgent forces along the Urgall Depression crushed the Salamanders and Raven Guard in a terrifying vice, and cut them to pieces in a murderous storm of fire and blood. Warriors of the Alpha Legion and Word Bearers followed their leaders onto the black plains of Istvaan V, their guns blazing and their Chainswords bright as they cast off the last remnants of their loyalty to the Emperor and turned their weapons on their brothers. What had begun as a battle had become a massacre, each pocket of Loyalist resistance gunned down with overwhelming superiority of fire, before the shredded survivors were hacked apart with bloody Chainswords.

At the forefront of the Emperor's Children, Lord Commander Eidolon and the swordsman Lucius led a contingent of their warriors into the heart of the enemy, killing with wondrous displays of bladework and howling shrieks of raw sonic power. The swordsman danced through the battle, his Terran blade carving a screaming, bloody path as he laughed in time with music only he could hear. Within hours the slaughter was complete and almost the entire strength of three complete Legions lay silent and dead on the tortured sands of Isstvan V.

Eidolon's Fate

Lord Commander Eidolon Corrupted

The Chaos-corrupted Eidolon, "The Soul-Severed", Lord Commander Primus of the Emperor's Children

Following the Drop Site Massacre of Istvaan V, Fulgrim and the Emperor's Children Legion were ordered to Mars by the Warmaster. But instead of following his brother's orders, the increasingly mercurial Primarch decided to disobey, and instead ordered his Legion to assault a Mechanicus Forge World known as Prismatica V in the Prismatica Cluster. Unable to deal with his lord's increasingly mercurial temperament as well as the increasing hostility of his fellow senior members of the Legion like Lucius, Lord Commander Eidolon questioned the utility of the Primarch's orders. This proved to be a tragic miscalculation on Eidolon's part. Unable to placate his angered lord, the few words he managed to speak on his own behalf inadvertently provoked the Primarch further. The paranoid, possessed Primarch believed that Eidolon was mocking him and planned to betray him. Quicker than the mind's eye could follow, the Primarch withdrew the deadly Kinebrach Anathame blade from its scabbard and beheaded his once-favoured son. Later, the severed head of the slain Eidolon was passed over the victory wine, the blood dripping from the grisly trophy and allowed to mix with the potent drink which was then shared amongst the senior members of the IIIrd Legion's inner circle.

In a moment of remorse, Fulgrim ordered his Legion's Chief Apothecary Fabius to restore the slain Lord Commander back to life. Fortunately, Fulgrim's killing stroke was a clean one, the blow struck with enough force and by a sharp enough blade that there was virtually no tissue damage beyond the exact point of impact. It was a killing blow of perfect precision, one that only a Primarch was capable of delivering. Utilising his skills as a master biologis, the Chief Apothecary was able to reconnect the nerve clusters at the base of the neck.

Unfortunately, Eidolon would live with pain like no other, driving the Lord Commander mad with joy. Every instant of life given to him would be spent in a symphony of pain and pleasure. Forever after, he would be referred to by his brothers simply as "The Risen." But after his ministrations by Chief Apothecary Fabius and his "miraculous" rebirth, Eidolon's body was an unpleasant collection of jerky tics and awkward movements. Fulgrim thought the Lord Commander's walk was ugly and foolish, and that he moved like a Greenskin. The very sight of the Risen offended his eyes, therefore he ordered the Lord Commander to stay behind him until he could perambulate with some grace. The Primarch believed that the fault lay with Fabius and his imperfect work. He would later punish the Apothecary for making Eidolon stupid and ugly.

Despite Eidolon's apparent death at the hands of his Primarch, Imperial authorities are still unsure as to Eidolon's current status. Official Imperial records seem to indicate that the Lord Commander was alive at least up until the Battle of Terra at the end of the Horus Heresy. Despite considerable effort, scholars in the service of the Inquisition have been unable to determine whether or not Eidolon survived the Siege of Terra. Unsubstantiated rumours claim that Eidolon has been responsible for hundreds, if not thousands, of gruesome raids on Imperial worlds in the past ten thousand standard years, and have suggested he may have served as a lieutenant to Abaddon the Despoiler, consort to Queen Sylelle and Chaos Champion of the Daemon Prince N'Kari. Yet, no Inquisitor has yet succeeded in locating the source of these rumours, but without indisputable evidence, the Inquisition will not declare Eidolon dead.

Attainment of Perfection

Like his Primarch Fulgrim, Eidolon was driven by the impossible desire to attain perfection in all that he did. Eidolon accepted nothing less than perfection in all of his endeavours, and worked ceaselessly to perfect his Legion's military operations. Each and every Astartes trained every waking hour for his assigned task. In recognition of his leadership abilities, tactical acumen and drive for perfection, Eidolon was recognised by his Primarch and became the first Space Marine selected by Fulgrim to lead an entire company of the Emperor's Children. As a company commander, he was further recognised for his superlative talents as a leader of men and was granted the esteemed rank of Lord Commander, one of only eleven in the IIIrd Legion.

The Primarch had personally chosen Eidolon and elevated him to this senior position within the Emperor's Children hierarchy, seeing in him the potential and qualities needed to lead the Emperor's Children. Eidolon was commonly regarded as the most proficient of all the Lord Commanders within the IIIrd Legion. Until the corruption of the Legion, Eidolon dedicated himself to mastering all aspects of warfare. His troops fought equally well in sieges, holding actions, rapid strikes and gruelling campaigns, never displaying any inexperience or inefficiency no matter what was demanded of them. Eidolon regarded Fulgrim as a father in the literal sense, considering his bond of gene-seed to be as strong as true parentage. Though he accepted that he could never equal the Primarch in power. Eidolon nevertheless spent every waking moment studying Fulgrim's tactics and strategies, his writings and orations, in the hope of growing as close to his leader's perfection as was possible.



The etymology of the name "Eidolon" stems from the ancient Greek eidōlon, which is an image or representation of an idea; a representation of an ideal form.


  • Horus Heresy: Collected Visions, pp. 75, 78
  • Index Astartes I, "Children of the Emperor - The Emperor's Children Space Marine Legion"
  • The Horus Heresy - Book Two: Massacre, by Alan Bligh, pg. 221
  • White Dwarf 255 (US), "Index Astartes First Founding: Children of the Emperor"
  • Horus Rising (Novel) by Dan Abnett, pp. 176-177, 187-190, 194, 197, 216, 219-220, 222-225, 229, 233, 236, 250-256, 258, 284, 289-290, 295, 315-316
  • False Gods (Novel) by Graham McNeill, pp. 90, 103, 308, 310, 316
  • Galaxy In Flames (Novel) by Ben Counter, pp. 23-26, 40, 46, 48-49, 51-52, 73-75, 79-80, 82-85, 93-95, 97-100, 108-111, 131, 139-140, 211, 217-218, 222-230, 233, 235-238, 243, 245-246, 248, 252-253, 256, 260, 265-266, 278
  • Fulgrim (Novel) by Graham McNeill, pp. 30-31, 52, 61, 63, 66-67, 107, 126-128, 179, 187-194, 205-207, 211, 220-221, 224, 230, 241-242, 244, 268, 271-274, 292, 296-299, 318, 328, 330, 345-347, 354, 361, 399, 401
  • The Primarchs (Anthology) edited by Christian Dunn, "The Reflection Crack'd" by Graham McNeill, pp. 10-13, 15-18, 36
  • Angel Exterminatus (Novel) by Graham McNeill, pp. 43-45, 91, 98-99, 132-136, 140, 183, 220, 239, 260-263, 270, 277
  • Forge World Character Series: Lord Commander Eidolon of the Emperor's Children


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