Kasimir de Valtos screamed in triumph as the Nightbringer bloated the chamber with dark energies, filling his mind with the most wondrous things imaginable. The eldar warriors fell back towards the Ultramarines, ready to fight their way clear of this nightmare they found themselves within.

But the Nightbringer was hungry for soul morsels, the darkness around its form swelling and billowing as though plucked by invisible winds. A deep throbbing beat filled the chamber as the metallic skeleton warriors turned their attention to the interlopers within their master's chambers.

Uriel shuddered in revulsion as the skeletal creatures marched towards him, raising their strange weapons in perfect unison. He dived out of the way, rolling and lashing out at the nearest warrior, the chainsword hacking through its legs and toppling it. He sprang to his feet as the metallic warriors opened fire.

Uriel watched with horror as Sergeant Venasus shuddered under an invisible impact, the fabric of his armour peeling away in flayed layers, his flesh following with horrifying rapidity. The sergeant dropped to his knees as his musculature was revealed then stripped away until nothing but his crouching skeleton remained.

Another Ultramarine died in agony as his body was stripped, layer by layer, by the skull-faced warriors' Weapons. Clawed hands grasped at Uriel, tearing at his armour, and he spun to face the metal skeleton he had just felled, the metal of its body re-knitting even as he watched.

He lashed out with his sword and put a bolt round through its ribcage. The warrior fell once more, but Uriel pounded the machine to fragments beneath his boot lest it somehow manage to regenerate once more. All around him was chaos.

Space Marines grappled with the metallic skeletons and were, for the most part winning, smashing them to the ground and blasting them apart with bolter fire. Sergeant Learchus tore one apart with his bare hands, smashing its skull to destruction against the floor.

But many of the deathly creatures simply picked themselves up once more, untroubled by wounds that would have killed a man twice over. Barzano fought beside Uriel, his glowing knife cutting a swathe through the enemy. His face was ashen and his movements slowing as the agony of his wounds began overcoming the pain balms.

The eldar fought alongside them and as Uriel kicked out at another foe, he kept a close eye on the aliens, ready to turn on them the second the machine warriors had been despatched. Their jade-armoured leader fought and killed with a deadly grace, his axe lashing out in a dizzying spiral of death. Wherever he struck a machine collapsed and each blow struck brought a screeching cry from the swirling darkness at the chamber's centre. But to Uriel it sounded more like a sound of amusement rather than displeasure.

The excrents snapped and bit, bearing their master's foes to the ground by sheer weight of numbers. The hideous alien weapons stripped great swathes of flesh from their deformed frames, but they fought on, oblivious to the rain of their anatomy, until there was little left save scraps of torn, convulsing body parts.

Uriel fought like he had never fought before, cutting, shooting and killing with a skill he had not known he possessed. His reflexes were honed to perfection. He dodged killing thrusts and lethal blows with preternatural speed, deflecting clawed hands and shattering metal skulls with dazzling skill.

The last of the metal warriors were smashed to ruins, their gleaming limbs and bodies scattered in pieces across the chamber's floor. Uriel heaved a painful breath, his side burning where an alien rifle had stripped away a portion of his armour and flesh. Clotted blood caked his head and armour where grasping hands had ripped into him.

A strange calm settled as Space Marines and eldar faced one another across the chamber. The Nightbringer stood unmoving beside the slab of what had been the top of its tomb, the cruciform shaped piece of metal still glowing with eldritch fire.

Barzano joined Uriel, his breathing ragged and uneven. Uriel saw the wound on his arm had reopened, blood leaking through the synthflesh bandage.

Kasimir de Valtos stood in the undulating shadow of the Nightbringer, his features twisted in savage glee.

He raised a finger to point at the Ultramarines and screamed, 'Destroy them! I command you!'

Whether the words were aimed at the eldar or the vast alien and its bodyguards, Uriel did not know, but it was the eldar who leapt forwards. Their leader made straight for him, his war-axe raised high.

The Ultramarines roared and charged to meet them, the chamber ringing with the clash of arms as battle was joined once more.

Uriel blocked a cut and stepped in to hammer his fist into the side of the alien's helmet. His foe ducked, slamming the barbed haft of his axe into Uriel's belly, ripping a long gash in his armour.

Uriel gasped in pain, powering the hilt of his sword into Kesharq's back, slamming the alien to the floor. He reversed the grip on his sword and spun, hammering the roaring chain blade downwards.

His opponent was no longer there, but somersaulting to his feet and spinning his axe at Uriel's head. A burst of flaring light exploded as Barzano's knife intercepted the blow and Uriel took advantage of the alien's momentary distraction to smash his sword into his head.

Kesharq saw it coming and twisted his neck, robbing the blow of much of its power. The whirring teeth ripped off his helmet, the dented metal catching on the loose skin of his face and tearing it free in a wash of blood.

Kesharq screamed in pain, his fleshless face hideously revealed. He staggered back, regaining his balance and blocked Barzano's reverse cut, deflecting the blade away from him and hammering his axe into the inquisitor's chest.

Bones shattered as the axe clove downwards through Barzano's ribcage, exiting in a bloody spray above his hip. Barzano fell, the power knife dropping from his hand.

Uriel screamed a denial, slashing at the alien leader's back. Kesharq spun away from the blow, trapping Uriel's sword in the jagged barbs of the axe blade and snapping it with a flick of his wrist. Before he could reverse the stroke, Uriel dived forwards, over Barzano's body, and swept up the fallen inquisitor's blade in time to deflect a sweep meant to remove his head.

Kesharq came at him again. The axe swept round and Uriel blocked it with the glowing weapon he had taken from Barzano.

Kesharq advanced more cautiously now, the red mask of his bloody features a truly repulsive sight, the twitching of glistening facial muscles clearly visible. He spat a mouthful of blood and charged, axe raised to smash down.

Rather than step back, Uriel ducked low and caught the haft of the axe on his forearm, feeling the force of impact crack his armour open. He roared, spinning inside the eldar's guard and gripped his arms, slamming his body into the alien and pulling.

The momentum of Kesharq's charge carried him sailing over Uriel's shoulder and he smashed into the ground on his back. Uriel spun the power knife and drove it with all his strength through Kesharq's breastplate and into his heart. The alien leader spasmed, dark blood bursting from his throat as Uriel twisted the knife in the wound and plunged it home again and again.

Yells and war-cries echoed around him, but all Uriel could see was the ecstatic form of Kasimir de Valtos at the chamber's centre.

He wrenched the knife clear of Kesharq's corpse and stumbled towards the man who had set these events in motion.

Kasimir de Valtos watched the furious battle raging around him with unabashed pleasure. To see so much blood spilt was pleasing to him, and the terrible things swarming through his head were a revelation. So much slaughter filled his mind! His entire being felt elevated as he savoured the thought that the things he was seeing and feeling were but the tiniest morsel of the bloodshed the Nightbringer could unleash.