Nox is Amy's warlock boyfriend, and no one knows his real name, and resident hunk of the Revolutionary Order of the Wicked, Nox trains Amy in magic and combat. His tragic past (all Glinda and Dorothy's fault) and his history with Mombi makes it difficult for him to trust anyone. Dorothy's armies destroyed his village, his parents were murdered and he was the only survivor. He was raised by the Revolutionary Order of the Wicked. All he ever had was the Order, until Amy came along. He used to be in a relationship with the half tin girl Melindra, which is explained a little more in the prequel ebook: Order of the wicked.
Nox is described as tough, serious, and attractive. With dark spiky hair, smooth olive skin, and pale gray eyes. He is known for being the strongest fighter the order of the Wicked have.
There also seems to be an inconsistency with his back story. In Dorothy Must Die he tells Amy that his family was drowned as Glinda was mining for magic, by hitting a water main. Yet in other versions of he states that his village had burned to the ground and he was homeless for a while until Mombi found him. This second story seems to the be the most popular as it has been mentioned a few times.
During the End Of Oz Nox is finally given a chance to be with Amy, after the war with the Nome King and the weird time travel ordeal with Dorothy he gets to live a normal human life in Kansas with Amy. The two of them go back to high school and start a new life. Dustin gets him on the football team and Amy still gets to keep her magic shoes. The last part of the book is them going back to Oz, only to discover that because Dorothy had stopped herself from taking over, the Wicked Witch of the West and the Wicked Witch of the East are still alive and now have Oz in control. The Order no longer remembers Amy, be feel as if they know her. The obviously know Nox, as a new adventure begins. (I think that's it for the series)