The 9 Sisters — Frank Buchan

In the ages after the fall of the greatest magical beings, in the years when witches have become little more than folklore, a great army moving south ravages a town where nine young women exercise enough wit to avoid becoming spoils of war. Their gambit is buttressed by an old wizard who serves the northern warlord's cause, or perhaps some cause his own. Under his tutelage the false witches become more than witches of old, and perhaps more than even their new master expects of them. And their journey alongside him, surrounded by the chaos of war, will test their secrets, their sisterhood, and their will. But, perhaps more than the threats of an unjust world, their youth and inexperience will cost them, risking their friendships, and perhaps undoing them entirely; because while they grow into their powers they must also grow into themselves.

This book contains violence, mature themes, and sex.