This Vicious Grace

Alessa is the Finestra, a divinely chosen leader whose touch is meant to amplify a partner's magic but has instead proven fatal to every suitor she encounters. With an impending demonic invasion threatening her island home, she must find a way to master her gift before her people lose faith in her. In desperation, she hires a cynical street fighter named Dante to serve as her personal bodyguard and help her survive long enough to save their world.