The Curse of Chalion by Lois McMaster Bujold
Nobleman and ex-galley slave Lord Cazaril returns to his homeland of Chalion after escaping captivity and finds himself appointed secretary-tutor to Royesse Iselle, second in line to the throne, after her brother Teidez.
Facing an unwanted arranged marriage to the evil Lord Dondo, Iselle begs Cazaril to do something to stop the marriage, resulting in Cazaril performing death magic in order to kill Dondo. Unfortunately, the use of death magic also usually leads to the death of the user, as well as the target.
Miraculously surviving the magic, Cazaril finds himself possessed by the spirit of Dondo and a death demon, and finds he now possesses second sight, which allows him to see an aura around the members of the royal family — a manifestation of a curse placed upon them many years ago.
Cazaril must find a way to rid himself of his supernatural hangers-on, whilst also trying to find a way to lift the curse which is upon all the Chalion royal family and stop Dondo’s brother, the Chancellor of Chalion, from seizing power on the death of the current ruler.
This is a superb fantasy novel, the first in the World of the Five Gods series, from multiple award winning author Lois McMaster Bujold. The prose flows effortlessly and the worldbuilding just seems to seep into the reader’s mind by osmosis — as an example of ‘show don’t tell’, this novel is a masterclass. The characters are all well-rounded and believable, and Cazaril himself is a protagonist who is crying out for further adventures. The plot ticks along at just the right pace and holds the reader’s attention all the way to the end.