Burning Ember by Evi Asher

Burning Ember, the first book in the Burning Miniseries, part of the Eternal series.

Burning is her curse. Saving her is his mission.

Born a pyro destined to die in her own flames, but raised a human, Scarlet is unwittingly thrust into the world of the Eternals, where she hurtles toward her ultimate fate.

A vision of a woman dying in flame has haunted Archer from his childhood, so when he learns about the rare pyro, he appoints himself her protector. How do you protect someone when everyone is out to kill or capture her, and how do you protect her when the greatest chance of dying runs in her own veins?