The Nichevo'ya are the shadow creatures of the Darkling. The Darkling dabbed in the abomination of merzost causing him to be able to unleash these creatures on grisha and innocent beings. In the end of Ruin and Rising the Darkling reveals his vast emount of power by turning Nikolai Lantsov into a Nichevo'ya. Nikolai showed to Alina a few times and returns to his normal self after Alina kills the Darkling. Nikolai describes his experiences as a Nichevo'ya and says that as the creature he could not read. Many people think differently of what the Nichevo'ya look like.