I like this retelling of Nick's story. We met him in the second full book of the Dark-Hunter series (Night Pleasures) while he worked for Kyrian. His character developed over the series being a good friend to Acheron and a Squire amongst the Dark-Hunters. It wasn't until he got involved with Simi that things went horribly wrong. 
 If you haven't read this far into the series, don't keep reading. Nick's mother died because of something Ash said and Nick sought Artemis because he wanted to kill Ash but that didn't happen. As it was Nick has become bitter and now hates Ash. Despite everything that has happened Nick and Ash still appear to be on the same side going so far as to help Ash save the woman he loves. But Nick still wants vengeance. 
 But that is all in the first time-line. In the Chronicles of Nick series Nick as his future self is changing young Nick's past. Young Nick is still working for Kyrian but Nick is learning who and what he is along with what and who people are around him. This in an attempt by his older self to save the world that older Nick is fated to destroy. 
 What I love is that while this is the overall arch of the series, Kenyon makes obstacles in each book for young Nick. In the first, it was to stop the Zombies from overrunning New Orleans and in this book it is to stop a soul stealing coach and stop 14 year old boys from dying. 
 It is like Nick has his own crew though at times, when Nick comes up against something he doesn't think he can handle, you keep wondering why he doesn't bring Ash into it since at this stage they are still friends despite older Nick's warnings that Ash isn't Nick's friend. Frankly, I think it is the anger talking. 
 This series is wonder with great twists and turns, new things to learn about different character and a whole subset of the Dark-Hunter world.