The Night Everything Fell Apart by Joy Nash

The Nephilim
Demon descendants of fallen angels battle for control of fractured Nephil magic and the mastery of the human race.
Arthur Camulus, the last living descendant of Merlin the Sorcerer, has inherited the vast and perilous magic of his ancestor. With gaps in his memory and blood on his hands, Arthur vows to wrest the leadership of the Druid clan from Mab, its beautiful and deadly alpha.

Cybele Herne joins Arthur’s quest though she knows defeat will bring death or enslavement. As the young lovers race to find the lost staff of Merlin—their one hope for victory—a second enemy surfaces: a rival Nephil who seeks to use Arthur to resurrect a deadly evil from the great sorcerer’s past.

One fateful night a beacon of hope shines. When Arthur reaches for it, the forces of Heaven and Hell collide.
And everything falls apart.