Dominator - Notable Members: Galan Dion - Galan Dion was a veteran member of the Iron Warriors' Tyranthikos who fought during the Great Crusade and Horus Heresy. He took part in the Battle of Phall, which saw his warrior society lose its role as his primarch's chosen honour guard. During this conflict, the Iron Warriors' hated rivals from the Imperial Fists Legion managed to board Perturabo's flagship, the Iron Blood, during the intense void battle and managed to reach the primarch's inner sanctum. Though the warriors of the VIIth Legion were all killed before they could inflict harm upon their lord, the failure of the Tyranthikos to halt the boarders' advance caused the Iron Lord to replace his organic honour guard with the Iron Circle Battle-Automata. Dion and his fellow outcast Dominator brethren constantly sought a way to regain their status and favour in their primarch's eyes. In the aftermath of the Battle of Phall, Perturabo led the Iron Warriors in a crusade of vengeance against the Imperial Fists. They targeted the world of Hydra Cordatus, which was guarded by the fortress known as the Cadmean Citadel that was manned by a force of Imperial Fists. Temporarily assigned to the 33rd Grand Battalion under the command of Siege Captain Ascari Valkar, the Iron Warriors launched a direct assault against the citadel. Despite his protestations against the siege captain's straightforward tactics, Dion had no choice but to obey his primarch's command and follow the upstart Valkar into battle. Despite their fierce resistance the Iron Warriors managed to breach the citadel's outer gates, however, they were set upon by an Imperial Fists Forge Lord who commanded five maniples of Castellax Battle-Automata, whose brutal firepower took a toll on the encroaching Iron Warriors. Were it not for the intervention of the Dominator cohort, the Iron Warriors would not have been able to regain their footing. However, after sustaining serious losses on both sides, the battle entered a bloody stalemate. With the loss of two-thirds of the 33rd Grand Battalion's Astartes, Dion and the other Tyranthikos could see that the siege captain's assault had failed. To save the remainder of their forces, Dion and his fellow Dominators forcibly removed Valkar from command and brought him before their waiting primarch. Without provocation, upon the primarch's order, his Iron Circle automata were ordered to execute the failed commander. The Iron Circle proceeded to render Valkar into bloody pieces of ravaged meat. Dion hoped that his actions would earn his primarch's approval, but Perturabo had none to give. He immediately ordered the Iron Circle to break the stalemate for the Cadmean Citadel's outer gates. Meanwhile, the Tyranthikos would be sent out once again to the front lines to serve and bleed like every other Legionary of the Iron Warriors.Legionary Khorius Rex - Khorius Rex was assigned to the 3rd Grand Company, 7th Grand Battalion during the Great Crusade and Horus Heresy. He was a veteran of the Tyranthikos, having trod a hundred worlds and more in the service of the Great Crusade. Once an ideologue, for Rex the Imperial Truth was long rendered down to but a kernel of cold, hard fact; the galaxy is no place for the weak and only those prepared to endure any hardship have any right to prevail. This moment of utmost clarity came when the 7th Grand Battalion was recalled to the Iron Warriors' homeworld of Olympia and bore witness to the rebellion that had gripped their primarch's world. In the bloodshed that followed, the man Khorius Rex had once been died forever, to be reborn and recast into a warrior whose heart was as cold and as hard as the ceramite skin of his Tactical Dreadnought Armour. Following the events of the Drop Site Massacre on Isstvan V, Khorius Rex took part in the IVth Legion's extermination operations in the aftermath of this campaign. Like many his master considered lacking or unstable, he was abandoned on Isstvan V when the bulk of the Legion was pulled out to pursue Warmaster Horus' war against the Imperium.