In The Cost of Two Hands, the antagonists are Cagen, Pain, and Fear. We don’t know much about them. A few years back when the winters started getting longer, they refused to pay for the food brought in by trains and just took it instead. This one selfish move damned Gang Gray to a slow starvation, and spurred Pain to devise a plan that leads to all out war with the other three Gangs. 

In The Sparrow and the Star,  Purity steps into the light, but her past is shrouded in the same fog that hides Soul and Haze. She dislikes and is distrustful of other women while she spoils and coddles the men. She is the Guardian of Purity, but for spoiler reasons, that’s all I can say about that.  She’s roughly constructed on the psychological of a serial killers mother and the psychology of the Nazis.