This was a gentle Fantasy with all the traditional, read archetypal, side-characters, but it's real strength is in being a great character-driven novel. 
 I consider Orlan and Flidais to be side characters in this story, with Blackthorn and Grim being the true gift from the author. With Blackthorn and Grim, this shouldn't be much of a stretch to see, despite Orlan's PoV time, because that guy was just too idealistic and good-natured and romantic a prince to make it as anything other than the subject of the novel and not the real meat. :) 
 Flidais was much worse: being the put-upon trope princess who serves as a backdrop and not a real mover. Which is a shame, because her real role (Sans Spoilers) did have quite a few more opportunities for fun and mayhem, but alas, this would not have served, likely even supplanting, the true tale of Blackthorn and Grim. 
 I've spent all this time on the side characters, but what's all the hullabaloo? 
 Think a revenge-filled wise-woman with a hulk of a devoted man watching over her, forced into service under the Fae to do good in a small little land, and you've got just the tip of the ice-burg. The novel was complete unto itself, with a good take on an old, old celtic trope, missing almost all of the tripe twists that are expected on such an old tale, resting all of its strengths on characterization, depth of world-building, and serious attention to detail. 
 I fully enjoyed the novel. It was such a nice change of pace from all the war-driven fantasies I've plowed through, recently, returning to the roots of Fantasy, as in Fairy Tales. 
 There's a lot of plot-drive about men and women, the nature of justice with rape, with perceptions and misunderstanding, as well as truly good-hearted people being wrapped up in the whole mess. (And bad ones, too.) 
 What can I say? I think this is no way a flashy novel or ranking up there as anything I'd peg as the standard, but as a very good novel with great characters, I think it's damn sweet. :)