His Darkest Salvation by Juliana Stone 
After six months in hell, Julian Castille has returned to the world a changed man. No longer the calm, powerful CEO, but a shifter fully embraced by the blood of his clan. Julian has one goal: find the key to the portal that stands between the human realm and unprecedented darkness—and win back the pieces of his soul. The last thing he needs is a distraction like the beautiful, enigmatic Jaden DaCosta.
Three years ago, a forbidden night of passion left Jaden forever altered: mated to Julian Castille–bound to a man who despises her. But the temptation to trust this darker, more savage—and more captivating—Julian is overwhelming. And as they fight for their immortal souls, their insatiable desire for each other may prove their fatal undoing
After six months in hell, Julian Castille has returned to the world a changed man. No longer the calm, powerful CEO, but a shifter fully embraced by the blood of his clan. Julian has one goal: find the key to the portal that stands between the human realm and unprecedented darkness—and win back the pieces of his soul. The last thing he needs is a distraction like the beautiful, enigmatic Jaden DaCosta.Three years ago, a forbidden night of passion left Jaden forever altered: mated to Julian Castille–bound to a man who despises her. But the temptation to trust this darker, more savage—and more captivating—Julian is overwhelming. And as they fight for their immortal souls, their insatiable desire for each other may prove their fatal undoing
More good old Paranormal Romance fun. This book is about the third and last Castille brother, Julian. Unlike his brothers Jaxon and Jagger, Julian didn't embrace his Jaguar nature growing up. Instead, he chose to become C.E.O. of the family business and was doing a damn good job of it. Three years ago Julian had a one night stand with a beautiful woman. Unfortunately, his tryst partner turned out to be the daughter of the DeCosta clan patriarch, a truly evil man and sworn enemy of the Castille Clan. Julian treated her like the manipulative scum he *thought she was (you know where this is going ) and never looked back. Then six months ago he was dragged into the shifter world to help his brothers and ended up being cast into Hell alongside his friend and ally Declan (more on his sexy self later).
Julian and Declan, who have had their souls shredded for the last six months, have been let out of Hell on a mission to locate a portal that can open the door from Hell into the human world. The catch is whatever is left of their souls will continue to fall away unless they deliver the portal to the mysterious "Bill" and pledge 1000 years to his service. Either way they have no chance of returning to their old lives.
Dysfunctional doesn't even begin to describe Jaden DeCosta's family. She hates her father and brothers, and with good reason. She is a fierce Jaguar warrior that has been working as a double agent with the two other Castille brothers to destroy her father. When she unknowingly met Julian (who didn't know she was a double agent) three years ago she made the mistake of giving into her inner Jaguar and claimed him as her mate. She has spent the last three years hating him while her inner soul still yearning for him. Her life pretty much sucks.
Jaden and Julian must work together to find the portal that will open the door to hell. Both of them are angry with themselves and each other for their current situation. They start in a very dark place, but fate has other plans for them. The mating bond between Jaguars is a powerful thing, more powerful than Hell itself. Once they get their head out of their butts and acknowledge their feelings they become quite the kick-ass team in the fight to save the world. This is definitely the darkest (heehee, pun intended) of the three Jaguar books, but I like my PNR dark so it worked for me. One of things Juliana Stone does well is provide background information at the right moment. I would find myself thinking "I don't remember this" and BAM! there would be the explanation I needed. You really don't have to read the first two books to keep up with what is going on in this one. However, I do suggest reading the others so you can get the smexy details of the other Castille brother's HEAs.
This story brings to a close the Jaguar series, but it segues nicely into the beginning of Stone's new series League of Guardians. The first book Wicked Road to Hell is Declan's story. He was a strong sorcerer before spending six months in Hell. He came back much stronger and with a darkness in his heart that he has hidden well so far. There is something about a man that can wield magic that turns me on ;)
