Mother of Shadows by Meg Anne

Helena’s life had always been quiet. In fact, she liked it that way. When her childhood friend returns to tell her she’s the prophesied ruler of the Chosen, her quiet life goes up in flames.
Suddenly thrust into a world of magic, Helena finds herself surrounded by a circle of protectors who swore their loyalty to her since her birth. Except for one: her Mate.
It’s not enough that she learn how to use her magic and undergo a trial to prove her worthiness; in order to claim her title, Helena must also find the man who carries the other half of her soul.
But the prophecy stands and all isn’t as it seems. There’s an enemy lurking within plain sight who will stop at nothing to destroy her.