Courting Darkness (A Defy the Stars Novella). Defy the Stars, #4

This is not a story of star-crossed lovers; this is a story of love that shines bright through the darkness and commands the shadows to still. Tobias of Vernanthia has been courting darkness since he was a child. A witch born with no apparent magic, in a world where magic means power, he was captured and abused by the queen of the rival coven. He thought he'd buried the darkness deep inside him, finally finding love with the man he had known since they were boys, but now the trauma of his past threatens to cast shadows on any chance of happiness.
Mercuree of Vernanthia has always embraced the darkness, the King's assassin who can bend the shadows to his will. He had made peace with who he was, and never considered that the boy he had loved in secret for years could reciprocate those feelings, not when Toby was so ashamed and scared to admit who he really was. The Country is veering towards being united once more and yet, Toby pulls further and further away from him leaving Mercy unable to do more than hold on to the spark of hope.
In that sliver of hope the past tensions between the covens threatens to be the end of not only their tremendous love story, but also their lives.