Not as good as the first 4
I started reading the Skulduggery series despite the awful title for the sexual elements as fluff reading. I found that the story was far more interesting and compelling than I expected and have been thoroughly enjoying it. The sex elements are minimal, and reasonably written, if a little repetitive, but the story itself is good. The author has taken pains to develop a rich and fairly unusual fantasy genre environment. The basic idea of the first book has been pushed to greater heights creating the basis for a more epic saga.
That being said, I was greatly disappointed in the end of the 5th book. It feels that the author is getting sloppy or lazy in his writing. There was a bit of this in the 4th book, here and there, where circumstances would develop contrary to notions previously established in the book, but this 5th book just flat unravelled in the last third of it. Where before it was just a line or two of character impression of the world view which would end up either being forgotten or contrary, the last portion of thus book changes the foundational morals of the protagonist and his group to a severe degree as to turn him from a person with a strong moral center driving his actions and establishing the premise for his followers and the mystical keys to want his leadership, to being a simple crimelord, dismissing the value of life unnecessarily, seemingly uncaring about collateral damage. On top of that, he starts to manipulate, cheat, and scheme against others as previous antagonists have done against him with no justification other than beating them to it. It skews the underlying moral standard of him being in the right to change things for the better by having him lie in the dirt with the other dogs, making him no better. Feels like the author painted himself into a corner not knowing how to get past the guild master and city watch captain, and took short cuts trying to wrap the book up quickly to do it. Again, lazy and sloppy at the end of the 5th book in an otherwise well developed series.