Curse of Magic by K. M. Shea

Evariste is gone.
When he sacrificed himself to save Angelique, he was taken in her place. Now everything has gone horribly wrong.
The magic council is too tied up in its bureaucracy to launch a real search effort. And though they have chased every clue, the other enchanters have failed to locate even a hint of him.
With time ticking away, Angelique decides to do what no apprentice should ever do: set out on her own.
As her search for Evariste leads her across the continent, she uncovers magic being used in dark and evil ways that hasn’t been seen in centuries: a prince cursed to live as a beast, a land ruled by an evil ogre, and a selkie enslaved by a sea witch.
None of these things should be happening. But they are.
Fighting these dark powers will require magic Angelique has never attempted before, and demand more from her than she’s ever been able to give.
In the growing darkness, can Angelique harness her deadly magic without harming others? And how will the magic council punish her for her unsupervised spells?