Before being captured and enslaved in the Salt Mines of Endovier for a year, Celaena Sardothien was infamous for being Adarlan’s most dangerous assassin. At only eighteen years old, Celaena has spent most of her life training with Arobynn Hamel, the vicious King of Assassins, who turned her into a killing machine. However, despite her lethality, Celaena is a fun-loving, compassionate young woman. Throughout the story the people she grows close to express disbelief at the fact that not only did she make it past the expected survival of three months in Endovier, she survived an entire year, and came out of the experience still able to laugh and find life worth living. In short, she has an unbreakable spirit even after living through such a dark past. 

Celaena is a mixture of conflicting forces: good and evil, strength and softness, rage and humanity. Her past is filled with trauma—including the deaths of her parents and her best friend, her capture being a result of a betrayal, and the loss of her magic. Because of this she is often described as having a seething, dangerous amount of anger within her, even while she comes across as relaxed and confident. Her anger emerges in her aggressiveness towards anyone who tries to put her down, and often drives her to viciously attack her tormentors. Chaol and Dorian both struggle to reconcile her kindness, sweetness, and beauty with what they have heard about her as an assassin, and the ferocity they see in her during the competition. In the end, Celaena proves herself to be a loyal and devoted friend to both of them, as well as a cunning survivalist who dances on the line of morality.