Esmeralda is the headmistress of Kimberly Magic Academy. Her fame—and infamy—extends far beyond the Union’s borders. Due to mysterious circumstances, she is afflicted with strange, untreatable headaches.

Spoiler

Esmeralda is able to devour the souls of mages she has defeated. She inherited this ability through her clan's vampiric ancestry, and has used it to consume the souls of over one hundred mages, starting with her former comrade and Oliver's mother, Chloe Halford. Her repeated usage of this ability is the cause of her incurable headaches.