The portal tore wide open. The jaws of the monster opened as if to swallow the materium. Then there were shadows in the light. There was heaving, scrambling, leaping movement. Unclean shapes charged down a tunnel of nothingness towards the chamber. They were moments from taking on form. The Lion braced himself for their arrival, the sword crackling with power eager to burn the daemonic to ash. Guilliman raised the Arbitrator.

Another shadow appeared behind the others. It was much larger, a mountainous shape that strode over the smaller beings. It was powerful, gathering material form to itself faster than its kin. It appeared to rush forwards suddenly, and its bellow of rage preceded it out of the portal. The silhouette became defined. The Lion saw six massive legs, arachnid in shape yet machinic in their angularity, supporting a massive torso. It swept a forelimb ahead, and the claw smashed clear of the portal. Muscle and metal were fused in the shape of a vice larger than a man. It caught the Lion full in the chest. It knocked him across the room, then slammed into Guilliman’s flank, hurling him into the flowing stone of the left-hand wall.

The towering daemon forced its way through the portal, its sheer size smashing the walls of the chamber. Its horned head looked down on the primarchs twenty feet below. Its gnarled, muscled flesh was the crimson of rage. Its other arm held a sword twice the height of a man. One of its legs came down on the remains of the altar and smashed them to fragments. Roaring its challenge, the daemon charged the primarchs.

Sanguinius was in a cavernous hall. There were mountains ahead of him. Their flanks rippled, worms under flesh. Eyes opened and closed down their length. Maws gibbered at their base. Tongues thirty feet long licked up at the eyes. The mountains heaved. They were living things, yet there was metal in them too. They were engines, larger than a capital ship. The hall was a nightmarishly huge enginarium.