The Legio Oberon ("Death Bolts II") is a Titan Legion of the Collegia Titanica, one of the military arms of the Adeptus Mechanicus. Hailing from the Forge World of Anvari, the Legio Oberon were famed for wisdom beyond their years.

Despite joining the Great Crusade in its final days, they soon amassed a string of victories alongside the Ultramarines Legion, utilising the superior tactical knowledge of their princeps to unleash bold assaults intended to dismantle their opponents' tactics.

Legion History

Legio Oberon Warhound Titan

Legio Oberon colour scheme as displayed by the Warhound-class Titan Feram Lex.

Notable Campaigns

  • Battle of Calth (005.M31) - The Legio Oberon was one of several Titan Legions called upon to muster at Calth for the campaign against the Orks of Ghaslakh. However, the Word Bearers Legion and their Adeptus Titancus allies loyal to Horus' cause soon revealed their hand and at a prearranged signal the Traitors struck. Across Calth, on its sister worlds and moons, and in the void throughout the system, the Word Bearers and their allies unleashed a devastating surprise assault. The Loyalists would sustain severe losses and the surface of Calth would be rendered uninhabitable due to the perfidy of the hated Word Bearers.
  • Shadow Crusade (007-008.M31) - When the Horus Heresy erupted, the Legio Oberon remained loyal to the Emperor. It served alongside the Ultramarines Legion during the campaign remembered as the Shadow Crusade, and fought with the Primarch Roboute Guilliman on Nuceria, the homeworld of Angron, the Primarch of the the World Eaters Traitor Legion. The Loyalists failed in their attempt to defeat the World Eaters and their allies the Word Bearers in the course of their genocidal campaign to eradicate the people of the world that had so abused the World Eaters' Primarch.
  • Crusade of Iron (ca. 008-010.M31) - Tetaros Kast, Master-Princeps of Battlegroup Avalon of the Legio Oberon was one of the few Princeps to fight on Calth and return alive. He brought word to the Forge World of Gantz, homeworld of the Legio Praesagius, of the fate of their fellow Titans and the betrayal that had occurred on Calth. The Traitor Legions were at large among the Five Hundred Worlds of Ultramar, and their very survival was at stake. Princeps Dae Vergos, Master-Princeps of the Legio Praesagius Warlord-class Titan Pride of Konor, assumed the mantle of Princeps Ultima and swore vengeance upon the Legio Infernus. He vowed to purge the Five Hundred Worlds of the Traitors' god-engines. Already astropathic cries for aid were reaching Gantz, as the Word Bearers and World Eaters Space Marine Legions, alongside the Legio Infernus, Legio Audax and Legio Mordaxis, spread out from Calth, bringing ruin and despair to the Five Hundred Worlds. Heeding the call of Gantz, Mechanicum fleets gathered, Battle Titans in their holds. Vergos sent emissaries to gather the Legio Oberon and summon the Legio Lysanda back from the Eastern Fringe, while missives were sent to dozens of Knight houses throughout the Five Hundred Worlds, calling in debts of honour. Multiple houses heeded the summons, including House Orhlacc, House Vornherr and House Vyronii. In spite of the betrayal brought to the Five Hundred Worlds, Legio Praesagius gathered its allies and convened its councils of war; the horrors of that the Loyalist Titans had faced at Ithraca on Calth would not go unanswered. Princeps Ultima Vergos promised her allies and her fellow Princeps that the Fire Master of the Legio Infernus would face the fury of those still loyal to the Imperium, and wherever the Traitor Titans set foot upon a world, they would find only death. Other Imperial forces soon flocked to their banner and the Legio Praesagius and their allies repeatedly clashed with Horus' forces. This Crusade of Iron would leave worlds burned by its battles and hideous and terrifying weapons were unleashed, such as the Psi-Titans of the Ordo Sinister. While it raged, the Loyalists fought to preserve the Ultramaran way of life, while the Traitors desired only to leave ruin in their wake.
    • Battle of Ulixis - The Wyrm's Lair (ca. 009.M31) - Ulixis was used as a staging ground by the Legio Infernus to both harm Ultramar and deal severe damage to the Loyalist forces. Ulixis was one of the principal producers of munitions in Ultramar and, knowing its destruction would deal a severe blow to the Ultramarines' effort to rebuild, Princeps Maximus Horgoth Nyr of the Fire Masters set upon the world. In truth, the Legion's invasion was the first step towards springing a trap upon the Loyalists. When a combined force of both the Legio Lysanda and the Legio Oberon were drawn to the world, they found its surface devoid of Traitor Titans despite reports to the contrary. It was then the Traitors sprang their trap, seizing control of the planet's orbit and unleashing a fierce orbital bombardment upon the Loyalists on the surface. Though the initial bombardment was devastating, most of the Loyalist forces were driven into the system of caverns beneath the surface, forcing the Fire Masters to commit to a series of running battles beneath Ulixis. For solar days the two Titan forces fought in the dark, their massive weaponry tearing apart the guts of Ulixis. It was within the Wyrms' Lair, a vast cavern littered with the remains of the burrowing creatures that had carved it long ago, that the conflict came to a head, both sides committing their forces in an effort to eradicate the other. As the fighting raged between the two opposing sides, Princeps Raynal Hess in his Warlord Titan Astra Obsurus, leading a Legio Lysanda Myrmidon maniple, charged out to meet Princeps-Maximus Nyr and his Warlorld Titan Mons Ingnum in battle. However, Hess was unaware of Nyr's fellow supporting Fire Masters Titans, which laid in waiting. Their combined volleys crippled the legs of Hess' Titan. However, before the Traitors could strike the killing blow, Hess overloaded his Titan's reactor, and the pitch darkness of the Wyrm's Lair turned to blazing day. When the explosion finally receded, those Princeps still in functioning war engines were surprised to see the light remained, for a massive hole had been blown in the cavern ceiling, and a stairway of rubble and broken Titans led up to it. More surprising still was the vox message that came streaming down across all bands -- the Loyalist fleet had returned with reinforcements, and the Traitors were in full retreat. Kast rallied Legio Oberon and the survivors of Legio Lysanda, and pushed the Traitors back. Though Nyr and many of his Titans managed to escape, their hold on Ulixis was broken, and perhaps most crucially of all, the Loyalists had driven the Fire Masters back, disproving the invincibility of their enemies.
    • Ambush at Espandor (ca. 009.M31) - In the wake of the conflict on Ulixis, the Loyalists sought to press the advantage, working to divide the Traitors in order to more efficiently dismantle their strength. When word reached the Legio Praesagius of a gathering Traitor invasion intended to seize the Agri-world of Espandor, the Loyalists laid plans to intercept the Traitor efforts, focusing their forces on the Boreaus Agri-sprawl, a heavily developed area containing a maze of feed-towers and macro-granaries that would serve to negate the numerical advantage of the Traitors. Though only a handful of Titans from the Legio Praesagius could be mustered, they were supported by several maniples from the Legio Oberon, alongside dedicated companies of both Titan-killer infantry and super-heavy tanks. Amongst their number stood the Psi-Titan Occedentalis-Damysus, the Warlord-Sinister-class Titan lending its support to Princeps Ultima Dae Vergos' forces for reasons known only to its Preceptor-Intendant. Having marshalled their forces, the Loyalists hoped to spring a devastating ambush on the approaching Traitor force, consisting of Titans drawn from both the Legio Audax and Legio Infernus. Much to Vergos' frustration, Horgoth Nyr did not command the enemy Titans. Princeps Tesarius Orcan Rex, as pitiless a leader as Nyr, led the Fire Masters and, supremely confident of his gathered force, he strode into Vergos' trap without a second thought. Orcan's Warbringer-class Titan God Hammer led the Fire Masters into the Boraes Agri-sprawl, where the Loyalist forces laid in waiting. The Fire Masters' own supporting Secutarii and Dark Mechanicum war machines moved out into the ruins left by the Titans, their job to root out any stragglers or survivors. Beyond the edge of the storm, in the hinterlands surrounding Boreaus, Dae Vergos and the Loyalists waited. Only the Psi-Titan Occedentalis-Damysus advanced upon the city, cloaked in a shroud of psychic energy. The Occedentalis-Damysus, tasked with striking the opening blow against the Traitors, found its talents stifled by the forces the Traitors employed. With the Psi-Titan brought low by packs of Legio Audax Warhounds hiding amongst the very buildings Vergos sought to use against the Traitors, the Loyalists were forced onto the back foot. Utilising Ursus Claws, the Legio Audax wolf pack dragged the larger Titan to the ground, like a bear brought down by hungry wolves. In an effort to secure victory, Vergos ordered her forces into the city in order to limit the numerical advantage of the Traitors, drawing them into a bitter, close-quarters fight. Meanwhile, the remaining Loyalist Titans advanced from the woods, their weapons pummelling the invaders. Vergos raced to move her Titans into the city where they could take cover from the enemy's superior numbers. Amid the devastating crossfire, the storm-coils surrounding Boreaus were hit repeatedly, dozens toppling in flames. Without the coils to hold it back, the storm raced in to cover the city. In the gloom, rain and flashing lightning, the two sides met with a mighty crash, like gods of old fighting over the fate of Mankind. Filled with battle rage, Vergos bulled her way toward Orcan's Warbringer, leaving savaged enemies in her wake, and destroyed the God Hammer by squeezing its head into scrap with its power claw. Her rage receding, Vergos realised that, despite the death of Orcan, her force was still badly outmatched. Vox messengers were coming in from orbit, the Loyalist fleet was heavily engaged and calling for retreat, and reluctantly Vergos had to comply. Yet someone had to stay and cover the withdrawal -- and for this task the Legio Oberon stepped forward. Its Titans accepted their fate willingly to save Dae Vergos and the remaining True Messengers. For their Princeps it was a chance to repay a debt owed since the battle at Ithraca on Calth, where they could not save their allies from the Traitors' surprise assault on the voidport. As the Legio Praesagius drop-craft made for orbit and their waiting fleet, the last communication from the surface was from the Legio Oberon maniples striding into the teeth of the enemy's guns, their vox blaring with a single repeated phrase: "For Ithraca!"
  • Plague Wars (ca. 111.M42) - The Legio Oberon came to the aid of the Ultramarines Chapter once again when it was counted among the Imperial forces dedicated to defending the Realm of Ultramar during the Plague Wars from the forces of Chaos in service to the Plague God Nurgle.

Combat Doctrine

Years spent fighting alongside the Ultramarines during the Great Crusade saw the Death Bolts II's Princeps learn much from the thorough tactics of the XIII Legion. Legio Oberon often employs trained strategisers whose sole duty is to watch the enfolding battle and devise counters to enemy strategies.

When the Titans of this Legion march to war their battlegroups advance in tight formation, each Titan supporting the next to stand resolute in the face of incoming fire.

The prosecution of war is, to the Princeps of the Legio Oberon, an exercise in mental prowess, and their Princeps participated in games of strategy when not upon the field of battle.

The use of Warhound Titans proved a key element of battlefield tactics within the Legio Oberon during the campaigns of the Horus Heresy. When enemy movements were known, maniples of Warhounds would often be dispatched to strategic locations long before the Legio marched.

Operating as a hidden vanguard, the Warhounds would conceal themselves until the enemy line moved past their position. When the remainder of Legio Oberon engaged their foes in battle the Warhounds would emerge, assaulting the rear of the enemy, sowing disorder and panic in their ranks.

The Legio Oberon’s fleshsmiths and mechnicians had a penchant for augmenting their Skitarii’s arms with heavy rotary cannons.

Notable Titans

  • Corinthian (Imperator-class Titan) - The Corinthian was an Imperator-class Titan of the Legio Oberon that survived the Word Bearers' treachery during the Battle of Calth. The Titan was later captured by the Legio Audax during the Shadow Crusade's battle for the city of Meahor on the world of Nuceria.
  • Panthera Rex (Warlord-class Titan) - Panthera Rex was armed in a manner favouring the bold and decisive tactics of the Legio Oberon. The Warlord was to play a significant role during the ambush on Espandor in the Crusade of Iron, launching devastating counterattacks against the hunting packs of the Legio Audax. Though outmatched in terms of speed, Panthera Rex unleashed the power of its Volcano Cannon at close range, scarring its own hull as payment for the death of the Traitors. However, the Agri-world would prove to be the Titan's grave, as it would fall alongside those of its Legion who gave their lives that the Legio Praesagious could withdraw.
  • Feram Lex (Warhound-class Titan) - The Warhound-class Titan Feram Lex took part in several notable campaigns during the latter years of the Great Crusade and the subsequent Horus Heresy.

Notable Personnel

  • Master-Princeps Tetaros Kast - Tetaros Kast served as a Princeps of the Legio Oberon during the Great Crusade and Horus Heresy eras. During the latter conflict he commanded Battlegroup Avalon when the Word Bearers turned upon the Imperium during the Battle of Calth. He was one of the few Princeps of the Legio Oberon to survive the onslaught of the Traitors' initial attack and was able to escape and bring word of the Warmaster Horus' betrayal to the Legio Praesagius on their Forge World of Gantz. Once the "True Messengers" learned of their brother Legion's catastrophic losses, their senior surviving Princeps, Dae Vergos, sought vengeance against the Traitors. She took command of the remnants of her Legion and declared the beginning of the Crusade of Iron against the forces of the Arch-Traitor. Master-Princeps Kast would later join the crusade and take part in the battle of Ulixis against the traitorous Legio Infernus, which ultimately ended in an Imperial victory.

Legion Appearance

Legion Colours

The Titans of the Legio Oberon are primarily painted orange with black striping.

Legion Badge

The sigil of the Legio Oberon is a black crown cleaved by a downwards striking thunder bolt. This symbol is centred within a white lozenge (diamond), outlined in gold.


  • Adeptus Titanicus: The Horus Heresy - Shadow and Iron (Specialty Game), pp. 8-12, 14, 20, 25-27, 66, 68
  • The Horus Heresy: Book Five - Tempest (Forge World) by Alan Bligh, pg. 51
  • Warhammer 40,000: Rulebook (8th Edition), pp. 158-159
  • Betrayer (Novel) by Aaron Dembski-Bowden, pg. 302
  • Butcher's Nails (Short Story) by Aaron Dembski-Bowden, pg. 201
  • Warhammer Community - Shadow and Iron: Crusades of Vengeance (05 February 2020)


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