Holy Union by AJ Ryder

When you love a fallen angel, sometimes there’s hell to pay.
Now settled in a new city, Filia and her protectors go about their task of helping the unfortunate, despite continuing to be hunted by demons at every turn. Complications arise when Lucilith tracks Filia down and begins wreaking havoc to draw her out.
All the while, subterfuge is woven from within the shadows.
The bonds of love will be tested and tempered, and familiar faces return for the battle to save Filia’s first love from the machinations of her father. But will their love be enough to withstand Lucifer himself?