L. A Weatherly
1) Angel burn
Angel trilogy (L. A. Weatherly) volume 1
In a world where angels are fierce stalkers whose irresistible force allows them to feed off humans and drain them of their vitality, a ruthless teenaged assassin of angels falls in love with a half-angel half-human girl, with devastating consequences.
2) Angel fire
Angel trilogy (L. A. Weatherly) volume 2
In the wake of the Second Wave, the angel menace escalates driving Alex and Willow to Mexico City where they connect with a fledgling group of angel killers who, although they accept Alex as their leader, remain skeptical of Willow, who is keeping a big secret.