The Shepherd of the Luna Wolves should have been considering how to leave this place with dignity—and waiting for reinforcements to arrive.
Then he would have realized that he could neither leave with dignity nor leave at all, and that reinforcements simply did not exist.
Fortunately, he was not thinking about that at all right now. The Shepherd of the Luna Wolves merely stood several steps above, one hand tightly gripping the still wildly struggling Emperor, his head raised as he stared at the scene before him in disbelief.
Any intelligent creature would have been dumbstruck by this sight. It was not Guilliman who shocked them, but the being on the throne behind the blue primarch—the Shepherd of the Luna Wolves felt as though his heart had stopped beating.
Upon that filthy throne, foul and warped flesh oozed unknown fluids. It was like two boneless creatures had been forcibly squeezed into a cramped space, countless disordered blue feathers caught between the folds of flesh, once more stained by pus and blood.
What had nailed the two enormous beings to the throne was an equally filthy, crimson-dark red longsword—the blade looked as though it had been pulled from the spine of some Monstrous Creature, its fishbone-like spikes brazenly thrust into the air.
That was... that was... that was...
The Shepherd of the Luna Wolves' pupils shook. He opened his mouth, but could not make a sound no matter what. His reason had already told him what the thing on that throne was, yet emotionally he could not accept it. His grip on the Emperor's hand tightened instinctively, unable to accept seeing such an undignified "Emperor," even if it was one from another fate.
The hurried footsteps behind the Shepherd of the Luna Wolves saved him. Horus came running over, gasping heavily.