Ash and Feather By S.M. Gaither

The second book of the Flame and Sparrow duology.
From the Ashes, a Goddess Must Rise…

After proving herself through a series of harrowing trials, Karys has found a home among the gods, alongside the Marr of Fire. Her new divine family and magic have allowed her to ascend from the rebellious, dangerous life she once led—yet the ghosts of past mistakes and betrayals linger.

Her once sworn enemy, Dravyn, understands the pain of lingering ghosts better than most. Haunted by the memories of the family he lost—and by the lives he took in retribution—the God of Fire now has one plan: Protecting the ones he has left at whatever the cost.

But the shadow of war is spreading across the realms. A war that will force both Karys and Dravyn to confront past demons. And when those demons collide, the resulting fires might burn everything to ash…

Forcing something new to rise if they want any hope of a future.