Cerys, the Fey Secret Agent

Cerys existed for unknowable millenia before being assigned to the Tylwyth Golgwr, the loose band of fey who serve the Unseelie Court in all matters human. Her knack for staying alive in the sun-blighted human realm made her a perfect choice for the job, as her relationship with the Court's current mistress. When the Court leadership changed, her patron wanted to get her as far away as possible. She metes out the Court's justice, or at least her interpretation of it, without question, despite the betrayal.