Frost to Dust by Myra Danvers

Their lives are linked.

Mila’s power has been stolen. Taken by a villain she can’t escape, her secrets all revealed. Held in thrall by an enemy she hates, she is consumed by the man whose mark circles her throat. Her wrists…
Her every action subject to the whims of Captain Asher Rawlings.
Controlling, jealous and possessive, he means to keep her for his own. To claim her magic and use it to rise within the ranks of the Caledonian army with a powerful priestess chained to his side—but Mila is untrained. Her magic volatile when it should be a soothing balm.
And what is dangerous to one, is deadly to the other.
A weakness in what should be an unbreakable bond.
In a place where even the slightest vulnerability is an open invitation for disaster, their bond is a lure for powerful men to strike without mercy.
On her knees but not defeated, Mila must choose. Give in to Asher and embrace her power…

Or let them both fall…