Lucifer, introduced in Cursed, the first book of the Fallen Angels series, now goes by Lucian and he has a problem. 

A disturbing problem named Anna Sill.
For the past ten years, he's struggled to understand why he has felt compelled to help her. Finally abandoning Anna to her fate, Lucian stubbornly refuses to have anything else to do with the human.
But fate and God are cruel mistresses, and Lucian finds himself face-to-face with Anna once again, though she's not the same girl he once knew.
Hell has many forms, and Lucian--its ruler--is about to discover Hell isn't just a place...it's a state of being.