Atonement (Heaven Sent #1) by J.L. Rothstein

SPFBO6

To Hell, this world is fractured and faithless, perfectly ripe for the picking. Sent by Heaven, Guardians defend against a malevolent onslaught of demonic intrusion. For hundreds of years the nine siblings of the O’Mara family have been engaged in this merciless battle, fighting to protect the souls of all humanity. Heaven and Hell have been waging this infernal war bound only by the rules of a contentious accord. On the anniversary of her husband Gabriel’s disappearance, Genevieve O’Mara’s lingering sorrow manifests into a murderous rage unfurled upon a demon. Vengeance is coming, not just for Genevieve, but for all those she loves.