Guilliman pressed his attack, battering at the daemon with a series of lightning blows that filled the space around him with sheets of fire. He carved away the tips of three more wing fingers, and when the creature recoiled, he sliced deep into its right shoulder. It screamed loud enough to interrupt the endless counting of the lesser daemons.

With a bellow almost as terrifying as the daemon’s, Guilliman hit its shoulder again, shearing off the whole of its right wing. The limb thrashed about on the floor as it dissipated back into the warp, and the daemon backed away. It attempted its scream again, but a slam of psychic force from the Space Marine Librarians stole its voice and sent it whimpering backwards.

‘I cannot be killed!’ it repeated. ‘I am death!’ Brass gears and diseased organs ran from its rotten innards onto the floor.

‘Then begone!’ shouted Tigurius. Together, he and the other psychic Space Marines bent their will, tearing open the rift the daemon had poured itself through. Purplish light spilled across the ruined cathedral. Rotting faces gathered there, eager to join their daemonic lord, but the power of the Space Marines held them back, preventing their ingress, and they howled with outrage.

Qaramar skittered back, lurching towards the rift. Bolt-rounds hammered into its side. Sisters and Custodians ran at it and drove their weapons into its flesh, all while Guilliman struck and struck again. The daemon was forced to defend itself, no longer able to attack, its remaining wing batted aside by the Sword of the Emperor with every swipe.

Then it stopped, and it laughed.

‘You… cannot… kill… me!’ it roared, and it reared up. A pulse of power upended the attacking warriors, sending them clattering down the steps of the altar. Dark light flared around it, and its body knitted its wounds, growing its wing anew. It beat both wings, now whole and webbed with patterned flesh. Gusts of poisonous air wafted back, and the daemon rose up over the battling host. Spitting balls of searing matter, it attacked again.

‘Lord Guilliman!’ yelled Maxim. ‘Force it back! Send it into the warp!’

Guilliman watched Qaramar swoop down the cathedral aisle, its wings almost brushing the sides. Its long head, now raw and bloody, its sockets filled with rolling yellow eyes, snapped at the warriors of mankind. The doors opened, and Tetrarch Felix came in, his Primaris Space Marines battering at the daemon with a torrent of plasma and bolt fire. But the daemon laughed, and dove at them, scattering them and slaying three.

‘I will end it,’ said the primarch. He cast about himself. He spied a set of crumbling stairs within the cathedral that ended in a broken gallery. They shook as he ran to the top, stone pattering on the ground. He halted at the edge of the missing floor.