Battle of Calth - Back From the Brink: High above Calth, in the master control room of the Zetsun Verid Fleet Yard, Roboute Guilliman confronted Kor Phaeron. Instead of fighting the Primarch in honourable combat, the Word Bearers' First Captain resorted to using the sorcerous abilities granted him by the Chaos Gods, slamming the Primarch of the XIIIth Legion against the chamber wall with a column of wretched, living darkness that burst forth from the palm of his right hand.Though shaken, the Primarch rose to his feet to face his attacker. Guilliman charged once more but was slammed back into a bulkhead by another powerful dark beam of eldritch power. Guilliman attempted to stand, staggered, then fell. The force of the Black Cardinal’s blow had been so vicious that the Ceramite of the Primarch’s breastplate was cracked. Guilliman coughed and blood dripped from his mouth. He attempted to stand once more.Kor Phaeron blasted him once more, this time with a strange negative electrical charge that caused Guilliman to seize as if he had been caught in a violent fit. The Primarch was left on his hands and knees, his whole form smouldering, his head bowed. The Word Bearers' Black Cardinal drew a Chaos dagger known as an Athame and stepped forward, the Primarch's fate in his hands. He had the opportunity to end the life of the great Primarch or, with his own hand, turn him to the Warmaster's cause.Just as the Word Bearers' First Chaplain Erebus had turned the Warmaster to the service of the Dark Gods on Davin's moon, so too, would Kor Phaeron achieve the impossible and bring another Primarch over to the service of Chaos. One cut of the Chaos-corrupted blade would damage Guilliman's sanity whilst Kor Phaeron took advantage of his weakened state, and slowly sliced away the inhibitions that kept him loyal to the False Emperor. It would be a fitting revenge for the Ultramarines' actions on Khur, to return to the court of Lorgar and Horus with Roboute Guilliman as a willing and pliant ally in their Great Betrayal.The vile Word Bearer stepped forth beside the wounded Primarch and put the blade of the Athame to Guilliman’s throat. The Primarch grunted through clenched teeth as the foul blade bit. Kor Phaeron attempted to cajole Guilliman into giving up and joining the blessed cause of the Dark Gods against the False Emperor. Guilliman only muttered in reply.With every single word an effort, the Primarch explained to the Black Cardinal that he had made a grave error, for he had chosen to toy with a Primarch rather than kill him. The arrogant Word Bearer merely smiled, confident in his inevitable triumph. Guilliman made Kor Phaeron pay for his hubris. Though its energy field had long since shorted out and failed, Guilliman buried his armoured Power Fist in the Black Cardinal's chest and ripped out one of his black, beating hearts.As one of the Ultramarines sergeants rushed to the wounded Primarch's aid, Guilliman ordered the sergeant to forget about him for the moment and to kill the planetary data network. Unable to figure out how to shut down the data-engines, Guilliman ordered the sergeant to shoot it. But the sergeant was out of ammunition, and so he unleashed his Power Sword instead in a shower of sparks and electrical fire.On Calth's surface, the remnants of the 4th Company prepared to face their doom, defiant to the very end. The bunker 300 metres below the guildhall trembled as it was continuously struck by devastating salvos of enemy fire. Suddenly, Magos Tawren informed her Ultramarines allies that their circumstances had drastically changed – two Loyalist Titans had vectored into the fight. One of them had already made a kill against one of the Word Bearers Traitor Titans. Reinforcements had arrived to supplement the beleaguered 4th Company. The reinforcements exploded into the Lanshear Belt from the east, fast and mobile. One of the four governing Ultramarines Tetrarchs of Ultramar, Eikos Lamiad, the Primarch’s Champion, lead a ragged host of Imperial soldiery collected from the desert and the burning hills around the Holophusikon.The reinforcements included a column of Land Raiders and other armour supported by three Titans: two Reavers and a massive Warlord-class Titan. An infantry force followed, moving rapidly. This force included mostly Ultramarines and Mechanicus Skitarii elements from Barrtor and the Sharud muster, but there were 20,000 Imperial Army troops as well, bringing lighter armoured vehicles and support weapons to bear. The relief force formed two prongs of assault. One was a Legion force led by a sergeant of the 112th Company named Anchise, and a captain of the 19th Company called Aethon. The other was predominantly composed of Imperial Army troops commanded by a Colonel Bartol of the 41st Neride Regiment, but it was now under the direct command of Eikos Lamiad and a lumbering Ultramarines Contemptor Pattern Dreadnought.Hol Beloth’s Traitor forces flinched at the unbridled force of Loyalists' coordinated assault. Beloth had not believed that the shattered survivors of the XIIIth Legion would be able to organise a concerted response with such precision and effect. The assembled survivors of the Calth Atrocity soon expressed their fury and their vengeance against the Traitors of the XVIIth Legion, inflicting massive damage upon the enemy. Despite their efforts, Tawren still lacked the necessary control over the planetary data network to unleash the kill code.Without warning, the planetary network was suddenly released from the Word Bearers' control by the events unfolding simultaneously in orbit and the swift strike of a Power Sword. The magos received the message: Control Suspended (engine failure). She did not hesitate to upload the kill code directly into the planetary data system which quickly burned through the corrupted numerics of the Octed scrapcode and allowed her to take full control of Calth's planetary defence grid.She then ordered the orbital defence platforms to launch a devastating weapon strike upon the Traitor forces at Lanshear. Server Tawren informed all the Loyalists surrounding the guildhall to brace for impact. A column of deadly vertical light then struck the city-zone around the guildhall in the northern depot area of Lanshear as the orbital platforms unleashed a tactical nuclear strike against the Traitors.It reduced Traitor Titans, armoured vehicles, Chaos Cult auxiliary and Word Bearers infantry formations to so much ash within only seconds. However, the weapon strike occurred less than half a kilometre from where the Loyalists had taken shelter from the coming impact.Yet, the Ultramarines and Imperial Army forces remained untouched, though some eardrums had burst and many Imperial Army troops suffered radiation burns to any exposed skin. Hot ash plastered the rain-soaked Power Armour of the Space Marines, spattering them with the remnants of their enemies. Ironically, the Ultramarines' ash-covered armour soon appeared a gun-metal grey, the old livery of the Loyalist XVIIth Legion.Magos Tawren next redeployed the defence grid elements available to her, hitting other surface targets. Simultaneously, she re-tasked the orbital platforms and began to systematically exact punishment upon the Word Bearers' fleet. It was now the crimson-hulled warships of the XVIIth Legion that were annihilated one by one. The dynamic of the entire battle had finally shifted in the Ultramarines' favour.