Draiss' own blindsense wasn't returning anything at all, so he had to guess it was an ambient residual of whatever controlled or created the Cave, or possibly a symptom of his own tainted, projecting into the area. Maybe both. He was getting tired, though, and began his finishing press, driving her weapons apart, opening her chest for the final attack, which he delivered without any real flair, just finishing off his own manifestation of his hatred. He had to admit, as he drove the attack home, it felt remarkably good.