Agnes Dei by Alexandra Berrocal

This story is about a Unitarian Universalist nun and her werewolf best friend, one thousand years into the future. Therese is a sadistic border guard who is seeking revenge on a fellow guard who attacked her. Agnes is a wayward Unitarian Universalist nun, who persuades Therese to set her free and follow her back to her convent. When Therese's adopted son gets involved, things get complicated.