Shield of Sparrows by Devney Perry

If you’re not terrified, you’re doing it wrong
Long ago, the gods unleashed monsters upon the five kingdoms of Calandra to remind us that humans are insignificant—that we must pray to the gods for mercy throughout our fragile, fleeting lives.
I didn’t need a deity to remind me I was powerless. Being a princess had never been more than a performance—twenty-three years of empty titles and hollow traditions. My sister revels in the spectacle, basking in the attention and flawlessly playing her part. I was never asked to be part of the charade.
Until the day an infamous monster hunter sailed to our shores. The day a prince walked into my father’s throne room and ruined my life. The day I married a stranger, signed a magical treaty in blood, and set off across the continent to the most treacherous kingdom in all the realm.
That was the day I learned that not all myths are make-believe. That lies and legends are often the same. And that the only way to kill the monsters we fear was to become one…