Nisroc is a Raven Mocker introduced in chapter three of Destined. Kalona has gone to find his sons and he finds only seven of them. Nisroc appears to be the leader because his speech is much more defined than most Raven Mockers. Kalona orders him to find the rest of his remaining sons and bring them to this place. He desires his sons to help him destroy Neferet because he has grown to hate her.
Nisroc and the other six Raven Mockers are completely horrified that Rephaim has chosen the way of Nyx, the Goddess of Night. Kalona assures himself that he was convinced by the Red One, Stevie Rae Johnson, and that soon she will reject him and he will join his brothers here, in the woods, to help Kalona defeat Neferet.

Kalona sends Nisroc and two of his other sons to find Rephaim, to spy on him and to give a message to him that even though he has left the side of his father, he is always welcome back there.