Shades have the special ability to control darkness with a substance called Shadowvapor. This allows them to talk secretly, somewhat like transmitting to another person when their shadows cross, the shadow-whispering. A shadow-whisper is when a Shade's shadow carries their consciousness so only the receiver can hear the message. Shades can take a reading of a person's potential for darkness.The opposite substance to darkness is Illumination. A balance of both is good. They can also disguise people so that they are hard (but not impossible) to see, but this trick does not work close up.
*SWM has confirmed that this alternate spelling was a typo in the first printing of Neverseen