plasma

Message chimes alerted her to power armour signatures moving in from the south-west. She swung about a little to see, and caught sight of golden figures carving their way through a horde of cultists seeking to trap them at the plaza’s edge. Though surrounded, their height and the splendour of their panoply made them easy to see. The Emperor’s light shone from His Custodians, and she felt her heart soar at the sight. Their battle spilled further onto the plaza, drawing away from the ruins, and gunfire from the bastion immediately began to track them, slaying the ragged hordes besetting them, but leaving no mark upon the golden giants. They moved through plasma blast and las-storm unmarked, their weapons rising and falling in sprays of blood and searing displays of weapon lightning.
‘The Adeptus Custodes are here,’ she said, her voice full of triumph.

Gate of Bones