Persuasion — Frances Stockton

They have lived for centuries. An ancient, secretive race of were-panthers faced with near extinction. To assure their survival they must conceal their identities and abilities, while protecting mankind from an unimaginable, primordial evil.
Persuasion: The Abcynians, Book I
As an Abcynian Elder, Garrick Forrester has survived wars, plagues, and arranged marriages. Nothing he's experienced prepares him for the discovery of his mate living in his demesne, or for her resistance.
While aiding a child, Aisley Reeves is rescued by the Earl of Danford, whom a village healer should never dare approach without being summoned. At first, she is fascinated with the dark, mesmerizing lord who tempts her in a way no man has ever done. After he claims she's to become his betrothed, she balks.
Already fearful her work and red hair might cause some to brand her as a witch, she believes it is best to keep her distance. When Aisley suffers a near mortal injury at the hands of his enemies, Garrick must gain her trust so that he can protect her. But can she trust her life to a man who is far more than…human?