Crypt King by TL Reeve

There's a lore about a Crypt King who rules over the forbidden cemetery and collects all the lingering souls. His three companions a step behind... Isa DeCuir has been marked... From the moment she was born, Isa has had a target on her back. After a horrible accident claimed the lives of her parents along with her best friend, Keres’, father, strange things began to happen—including her inability to control her spellcasting. Mads Billiot has been waiting for this moment all his life... He has honed his skills, chosen his partners wisely, and put into motion certain schemes to not only protect his future bride, but to also break the network of witches within the Grand Du Parish. However, there is a nasty secret buried with the dead that threatens everything he’s accomplished along with his future bride. Ethan Guidry has walked the earth for over a millennium... As a Grim, he has seen what can happen to lost souls or those who feed themselves to the Crypt King. There’s no way Ethan would allow Isa to become another of the King’s hapless victim. He’d do anything for the Witchling including becoming her familiar and sharing his life with her. However, there are strange happenings afoot, and his wishes might truly be nightmares. All Hallows Eve approaches... As the veil between the living and the dead thins, can Mads and Ethan protect Isa from the truth? Or will Isa become the next victim of the Crypt King? This is a enemies to lovers, love triangle, full-length 95k+ book.