Sweet Ruin features two new characters, Rune and Josephine, rather than continuing on with existing characters. Although Thad and Nix are in the story, no other continuing characters are really involved, but rather new secondary characters. This helps build the upcoming Ascension, as well as outlines the Morior and their role in the Ascensions of the past and current. 
 Dark Fey...poisonous to all those who come in contact with his blood, Rune is half fey and half demon. Rune struggles to keep his past in the past, but never truly left if behind. Ever loyal to the leader of Morior (Orion), Rune sets out on his new mission to kill Nix. As an archer and dealer in secrets he is the best for the job. At times I found Rune likeable, but overall I was not sold on his character. 
 'Dead and dead', Josephine is a new breed in which we have only had minimal contact with...she is Thad's older sister. Age eight, Josephine and Thaddius (infant), wandered the streets. Jo's character is brash and she can't seem to stay out of trouble. Which leads to the fated day, she had to let Thad go. Jo tells it like it is and doesn't really ever become a likeable character and at times comes off as whiny. 
 Crossing paths and destined to be fated, Rune and Josephine struggle with their growing relationship and 'saving' Thad. I started reading the series this summer, so I am pretty familiar with the other stories. I can say, however, I was not as impressed by this story as the others. Overall the story was good, but I feel within the series there are others that far surpass Sweet Ruin. Looking forward to seeing where the story goes now that the Morior are revealed. I received Sweet Ruin via Netgalley for an honest review.