Fallen angel-types make my heart go pitter-patter.
Revenant (Lords of Deliverance #6, Demonica #11) by Larissa Ione
HELL HATH NO FURY . . .
For five thousand years, Revenant believed he was alone in the world, a fallen angel beyond any redemption. Now he finds he has a twin brother who had all the light and love Revenant was denied. Caught in a tug of war between Heaven and Hell, he must weigh his thirst for revenge against his desire for a mysterious female named Blaspheme—a female whose very origins could deliver him into salvation . . . or destruction.
LIKE AN ANGEL SCORNED
Blaspheme has a deadly secret: she's the forbidden offspring of an angel and a fallen angel. Hunted by both heavenly and satanic forces, she has survived only by laying low and trusting no one. When Revenant claims he can save them both, how can she possibly believe him? But the powerful angel is persistence incarnate and for Blaspheme, there's no place she can hide in Heaven or Hell where he won't find her . . .