The Wicked In Me by Suzanne Wright

No one really knows what they are. Only that they’re the first civilization. Aeons, they call themselves. They’re immortal. Powerful. Secretive.
And they’ll come for her.
Witch Wynter Dellavale knows that for certain. Because in unfairly trying to execute her, they started a chain of events they’re struggling to stop. Needing safety, she flees to Devil’s Cradle, the home of monsters. A place for the outcasts, the fugitives, the crazies. A place ruled by the Ancients, seven beings who were once banished by the Aeons. Among the Ancients is the infamous Cain, brother of Abel and embodiment of jealousy – who, on another note, wants her in his bed.
There’s a heavy price for the safety the Ancients offer, but Wynter will have to pay it. She can’t take on the Aeons alone. And she has no intention of dying – been there, done that.
Not that she’ll be the easy prey the Aeons are expecting. They have no knowledge of the … thing that lives inside her. You see, when witches are brought back from the afterlife, they don’t always come back the same.
And they don’t always come back alone.