Now We Are Monsters. The Commander, #2

The Commander (Book Two)Carol Hancock is a victim of Transform Sickness, a Major Transform known as an Arm. After her escape from government detention, an established and mentally unstable Arm, Stacy Keaton, trained her in the Arm basics. The basics are not enough, though, and Carol's training continues, now with an explicit graduation test she must pass to get out of Keaton's hands and become a free Arm.
During Carol's training, the two Arms annoy one of the hidden powers among the Major Transforms, a master of Chimeras known as Wandering Shade. Wandering Shade and his Chimeras plot to take their revenge on the two Arms, in the process endangering Carol's hidden male Major Transform companion Gilgamesh as well as Keaton's Major Transform backer Tonya Biggioni. Carol must solve her graduation test before her own teacher suffers a psychotic break and kills her, and before the dangers of the outside world collide with the two Arms.