Broken Fates by Annie Anderson

Queen. Savior. Sacrifice.

The realms are fracturing—and Vale Tenebris stands at the center of the storm. With chaos spreading across the continent, Vale must harness the magic she barely understands to protect her kingdom and the ones she loves. The bonds with her mates have been tested, and the forces threatening to tear their world apart grow stronger by the day.
As ancient powers stir and secrets come to light, Vale is thrust into a race against time to stop a war that could consume the realms. But with enemies in every shadow and betrayal waiting at every turn, survival will demand more than magic—it will demand everything she has.

The fate of the realms lies in her hands, but at what cost?