Perspective Makes a Monster: Part One.” It is the first book of the On Cycles and Poetry series.

Monsters are made one way and one way alone. This is a terrible lesson to learn.
When Sorrel begins to learn it, he is a student of legends and unwillingly betrothed. By definition, his world is war-torn, and the demons known as the Ashtar clan are preparing to sweep his hometown out from under him. However, all these definitions gleaned from stale pages amount to exactly nothing when he ends up with a knife to the throat, looking a demon in the eye.