Vengeance by A.S. Fenichel

The demon master is out for revenge, and the gates of hell are flung wide. Only the purest love can force him back…

After a debilitating injury leaves Brice Lambert in agony, he’s relegated to teaching others to hunt demons. He knows all the secrets of the demon war and plans to die for the cause. Never did he expect his dreams of a loving wife and big family to come true, but the very witch who healed his leg is capturing his heart.
Abigail Higginbotham’s extraordinary power elicits fear and mistrust from the very people who should love her. Instead, they shuffled her around, depriving her of family and coven alike. Joining the Company of demon hunters brings her the closest thing to a family she has ever had. Forbidden to love, she risks losing everything for the man who has loved her for many lifetimes.
Together, they must find the key to seal the gates of Hell and lock out the demon master forever. Fail, and mankind is doomed. Succeed, and face death in the pit of Hell. A small price to pay for eternal love.