The Blood Plagues by Anavrin Jay

Dying women care not for the rulebooks of men, living women less still.

Ashara and Demetri dare only the briefest of touches, each kiss stolen under the cover of dusk. Tired of crumbs, they make a vow to indulge in the sin they both crave the night before their offering; one final act as living flesh before they are sacrificed to the Blood God.
But that was before. Before the acolytes. Before the inquisition. Before the penance.
Estranged for eight years, they reunite within Dendra’s Grand Templum mere hours before they are destined to die. When a druid is found slain inside its sacred walls, the sanctity of the Last Rite twists into a vicious hunt for answers only a brutal awakening can provide.

The druids will learn how a woman’s rage can rival the wrath of a god.