I didn't like this as much as it's predecessor Midnight Angel, but still enjoyed it, even though....
****SPOILERS*****
The hero cheats once, which is normally a 'throw the book across the wall and never finish it' moment for me. However, in this instance, I wasn't as offended as I normally would be. I think it was because it was made clear he didn't do it out of lack of interest in the heroine or a desire for anyone else. The H was so obsessed with the h that he planned to marry her for years (since she was 13) and schemed and scammed to get her to agree to a "marriage of convenience" with him. He was in serious denial and truly terrified of how much he had come to need Emma. It's not an excuse, but it worked within the context of the story and the h is definitely not a pushover, he definitely has to earn his way back into her life and bed. Also, it's not an affair and there's no detail. He goes out, get's drunk, and comes home smelling of liquor, sex and perfume. I assumed he was with a prostitute
I absolutely adored Lord St. Vincent in Devil in Winter, but never really considered him a dark, villainous antihero as some seem to. Spoiled and selfish, definitely, but I never took his "villainy" too seriously. Prince Nikolas, however, is more the genuine article. He is definitely a tortured soul and at least a borderline alcoholic. And he did have some pretty horrific traumas in both childhood and adulthood to contend with. In fact, a *trigger warning* for descriptions of childhood sexual abuse is worth noting. (Nikolas' father repeatedly and brutally raped his younger brother, who he was unable to protect). Not your typical "one woman hurt me and now I'm an ass" excuse for being broken.
I am as yet undecided on the reincarnation element. It was emotional and I cried when Nikolas "died" in that previous life, but part of me wishes he would have learned to accept his love for Emma in 'real time'. In fact, I think it would have made this a 5 star book for me.