Demon’s Mark by Ella Summers

The schemes of deities are always multi-course affairs.

Three years ago, gods and demons united against a common enemy. Now a terrible, ancient secret threatens to tear that alliance apart.
Leda Pandora, the Angel of Chaos, has a complicated family. Her father’s a god, her mother’s a demon, and her daughter is destined to one day become the savior of the universe . . . if Leda can keep her safe long enough to grow up.
Unfortunately, the universe might need saving a little sooner than expected.
Whole worlds are going dark, deities are dying, and both gods and demons are each blaming the other for it. Every day, the threads of peace grow weaker. The countdown to war is ticking, and if Leda can’t uncover the real culprit in time, the alliance won’t be the only thing in tatters—the whole universe will burn in the aftermath.

Demon’s Mark is the eleventh book in the Legion of Angels series.