Invitation
Khan's senses had long since gone beyond what anyone could consider human. That didn't only apply to his sensitivity. His ears, touch, nose, tongue, and eyes had also evolved, developing a connection to mana.
That had expanded the range of what Khan could feel, and not only in terms of depth. He could also sense things far away, which was exactly what happened now.
The mechanical noises and red lights were distant, but Khan knew what they meant. He had actually predicted a similar outcome. It was one of the possible consequences of his call.
However, the timing wasn't ideal. Khan was in a troublesome situation, and retreating would leave him empty-handed. He could still call the Tainted animals on a different night, but people might become suspicious, so it was better to get something now that he had the chance.