Arch-Centurion Carnac Commodus was a Veteran Astartes of the Renegade Astral Claws Chapter who served as the commander of the Strike Cruiser Hyrcania during the Badab War. Following the destruction of his home base on the Feral World of Shaprias by a Loyalist strike force, he craved vengeance and a chance to make up for his failings in the eyes of his lord.
Seeking assistance from his Secessionist allies, he found an unexpected ally in the Phaeton's Wrath, the flagship Battle Barge of the Executioners Chapter, and her accompanying Gladius-class Frigate escorts. The combined battlegroup attacked the Loyalist vessels, disabling the Salamanders Battle Barge Pyre of Glory after a surprise attack at the Warp-transfer point near Calah. They forced the mighty Space Marine starship's surrender.
The Astral Claws set about attempting to massacre their prisoners and harvest their gene-seed, but the Executioners would not countenance this vile action. They renounced their alliance with Lufgt Huron, the Tyrant of Badab, saying that the blood oath binding them had been violated. The Executioners freed the Salamanders captives and turned on the Astral Claws, taking more than 200 heads from their former allies in a single hour of furious conflict known as "The Red Hour." From this point onward, the Executioners Chapter became a rogue element in the conflict. High Mortiurge (Reclusiarch) Thulsa Kane came alone before the Salamanders' commander, Captain Pellas Mir'san, and presented a single gory object which he rolled at Mir'san's feet -- the head of Arch-Centurion Commodus.
Carnac Commodus was an Arch-Centurion, a specialist rank utilised within his Chapter to recognise Veteran Astral Claws chosen to command and if need be, punish the human Auxilia of the Tyrant's Legion. These merciless individuals were selected for their might of arms and utter devotion to Huron's cause. They were objects of religious awe and genuine terror by those they commanded, and also served as the eyes and ears of the Tyrant across his fledgling pocket empire.
Arch-Centurion Commodus commanded the Strike Cruiser Hyrcania. Based upon the Feral World of Shaprias in the binary star system of Lamptan, Commodus would launch corsair raids against Imperial shipping within the region. But in 911.M41, while the bulk of the Astral Claws' warships were away on some mission of plunder, a joint Loyalist Space Marine strike force composed of elements from the Salamanders and Minotaurs Chapters and aided by an Imperial Navy task force raided the planet and destroyed the Secessionist bastions and Tyrant's Legion training camps in a series of blood-soaked, close-quarter battles.
Fresh from their victory on Shaprias the Loyalist task force was unexpectedly struck by a powerful Warp squall and scattered en route back to Imperial-controlled space. Calamity was averted by the formidable skills of their lead Navigator, and only a single frigate was lost to the Immaterium, while the Salamanders' Battle Barge Pyre of Glory and the Light Cruiser Admiral Gregorius were turned back into the Maelstrom riding ahead of the stormfront and forced to return to realspace in the relative stability of the Calah Shoals within the Maelstrom's boundary to repair and refit. The Loyalists' arrival had not gone unnoticed, for soon news of their presence was carried to the Secessionists. The Astral Claws Strike Cruiser Hyrcania was still in the region, having found its home base on Shaprias destroyed.
Arch-Centurion Commodus craved vengeance and atonement for his failings in the eyes of his lord. But Commodus knew that alone his vessel stood little chance of taking on the wounded Loyalists. He sent an encrypted astropathic message seeking aid that was received by an unexpected ally in the Phaeton's Wrath, the Battle Barge flagship of the Executioners Chapter, and her accompanying Gladius-class Frigate Escorts, which had been taking on supplies at the uninhabited Ocean World of Deluge on the edge of the Magog Cluster. Their combined battlegroup attacked the wounded Loyalist vessels as they moved toward the Warp transfer point at Calah to embark once again. The Light Cruiser Admiral Gregorius was blasted to atoms in the opening salvo of the Secessionists' guns. The Pyre of Glory quickly proved to be far less easy prey. The Salamanders' mighty Battle Barge managed to repel the first boarding assaults against her and destroyed two of the attacking frigates. But after a three-hour-long running battle, the Phaeton's Wrath managed to entirely disable the Pyre of Glory's thrusters, leaving it dead in space.
High Mortiurge (Reclusiarch) Thulsa Kane of the Executioners Vox-signalled the Salamanders' vessel and offered them the chance for honourable surrender, vouchsafing passage for them from the war zone under oath not to take up arms again in the conflict. Captain Mir'san conceded to this demand, despite the misgivings of some of those under his command, knowing that to do so would risk his force being destroyed without being able to strike back at their foe. Having himself fought alongside the Executioners Chapter centuries before as a Scout Marine Neophyte, he trusted to their oath of offered surety. Both the Phaeton's Wrath and the Hyrcania drew alongside the battered Pyre of Glory and docked, Thulsa Kane personally leading the Executioners boarding party and accepting Mir'san's sword in surrender as the Salamanders stood down their arms. It was elsewhere within the great ship that the unthinkable occurred.
Thanks to the conditions of the surrender, Arch-Centurion Commodus led his own boarding party to seize the Pyre of Glory's armouries nearly unopposed. Heedless of the consequences, Commodus sought to breach the ship's sanctum vaults and seize not only the recovered Astral Claws gene-seed from the caverns of Shapiras, but also the Salamanders' own recovered stock from the fatalities sustained during the conflict. When the Salamanders' Apothecaries resisted this affront to their Chapter's honour, Commodus cut them down. He then unleashed his unfettered wrath upon the Salamanders, ordering the massacre of the Salamanders Astartes that they had taken prisoner. He ordered his "Corpse Takers" to strip them of their gene-seed whether alive or dead. A pitched battle quickly broke out across the decks.
As reports reached the bridge of what was happening, Thulsa Kane was incensed with murderous rage. Seeing this reaction, Mir'san wisely divined that the Executioners did not possess full knowledge of the heresy and blasphemy committed by the Astral Claws, perhaps having been deliberately deceived by the Tyrant of Badab. Controlling his own outrage, Mir'san poured deliberate scorn on the Executioners' leader, both for this breach of his word and the dishonour of standing by and allowing the Tyrant's sins to go unchallenged. With the reports of his Executioners' own eyes giving the gravity of truth to Mir'san's claims, Kane's wrath was terrible to behold. He declared that the blood oath binding his Chapter to Lufgt Huron's cause had been violated, and the dark stain of infamy the Astral Claws had brought upon them could only be washed clean by a river of Astral Claws blood. Those Salamanders Battle-Brothers that survived the battle that ensued later reported that a bleak madness came upon the Executioners at Kane's pronouncement, and that they tore into the Astral Claws with a murderous vengeance. The Executioners proved heedless of the risk to their own lives, and were satisfied only that their former allies would die by their hands regardless of the cost.
Captain Mir'san rallied his surviving Salamanders brethren and mounted a defence of the Battle Barge's inner sanctum, unleashing the power of the mighty Dreadnoughts, led by Bray’arth Ashmantle, upon the apostate Astral Claws. First the corridors and vaults of the Pyre of Glory and then the Astral Claws' Hyrcania ran red with Astartes blood. This dreadful battle became known in the legends of war as "The Red Hour," as every single Astral Claw Space Marine, Chapter serf and Servitor present was relentlessly hunted down and slaughtered. The Hyrcania was left a charnel house of decapitated bodies, as the Executioners took more than 200 heads from their former allies. Thulsa Kane came alone before the Salamanders' commander, Captain Pellas Mir'san, and knelt in the light of the burning sanctum braziers. Offering him no words, Kane presented a single gory object which he rolled at Mir'san's feet -- the head of the Arch-Centurion Commodus. From this point onward, the Executioners Chapter became a rogue element in the Badab War, supporting either side as the dictates of their honour demanded.
- Imperial Armour Volume Ten - The Badab War - Part Two, pp. 25, 30
- Forge World - Space Marine Badab War Characters Update Version 2 (6th Edition)