Dust to Smoke by Myra Danvers

Tritan’s last true priestess is gone.
Killed in a trap of her own making, Sasha was swallowed by righteous flames that consumed the only mentor Mila might ever know. And with her, the very last one standing between Mila and true annihilation is dead.
And now, no one can save Mila from him.
Asherholds a power never seen on this side of the veil.
He’s a better predator. One who will rewrite the laws of nature just to see her every whim satisfied. Her every need met, his obsession tempered by knees bent and bruised in service to his wicked desires.
And it was her own fault. All of it.
Guilt keeps her marooned on a lonely, forgotten spit of land, guarded by a man who holds all her secrets in a legendary vice of perfect control.
He feels everything. Covets every breath and gasp of pleasure as he lets her feast… but only if it’s from him.
And now, nothing matters. Not her grief or wretched self-loathing.
Defeated, her choices reduced to cinders in a smoking wreckage, she has to bend or she will break…
… when she was meant to burn…