Damn it!
The moment he saw that twisted brilliance, the old guard realized he had carelessly fallen into extreme danger—on this bleak, deep night, an unimagined and unnameable being had knocked on his door, and what was more deadly was that he had lit potent incense a few minutes earlier to extract secrets from the souls of two heretics!
That incense was powerful enough to construct the caster's desired deathbed illusions in the minds of the dead and greatly enhance the caster's own sensory range and mental acuity, which enabled him to discern the breath of the Profound Demons from the most subtle fluctuations in the consciousness of the two heretics—the side effect, however, was that his spirit sight was temporarily heightened, thus leaving him practically defenseless in facing the true nature of that Visitor at this moment.