Devil Bringer responds to demonic presence

And the Devil's Hand (Devil Bringer in the game) had one feature: it pulsed in response to manifestations of demonic power.

Nero looked at his hand to make sure that it was not a (his arm lights up if it’s a demon close to him) demon who had come to him. And if he really were, the hand would have definitely reacted.

The woman stood and silently smoked a cigarette. The hand was also silent, which meant that the guest was not a demon. Well, or a demon, but without a drop of power.