Good versus evil is a hallmark theme of the High Fantasy genre, and Maas explores this dynamic on the personal and epic scale through morally complex characters.

Through Celaena, Maas explores how moral good is defined by a person’s impact and intent. Celaena is unapologetic about her history as an assassin, yet she resists Chaol’s desire to reduce her entire moral being to her criminal past. She is ruthless in her pursuit of personal freedom, yet even from the earliest pages of the novel demonstrates concern for the wellbeing of others. Having just agreed to compete for Champion and eventual freedom, Celaena wants “to think of a celebratory tune, but [can] only recall a solitary line from the mournful bellowing of the Eyllwe work songs”(19), preoccupied by the suffering of enslaved Eyllwe rebels in Endovier. Celaena has made moral compromises for survival—all the while maintaining an inherent goodness. Most obviously, though as a child, Celaena wanted to be a healer, after being orphaned she was forced to become a professional murderer. Still, Celaena does not absolve herself of her own crimes, feeling “stained and tainted by her crimes” in Elena’s tomb (184).