Falling From Grace. Woven, #4

When Grace's brother in law leads an army to overthrow their mad king, she inspires the women of their village to become healers, witches and warriors. But once she gets Calvin on the throne, her world only becomes darker. Given all of the power of the crown, Calvin gives into his darker instincts. While Grace learns to be a witch and queen, Calvin slowly loses his mind. He becomes a crueler king than any the country of Calistar has ever seen.
Grace finds that her greatest challenge is overthrowing the king she put on the throne.