Khai is a blooded, young warrior assigned at birth to be the soul-twin and protector (The Shadow) to princess Zariya. There has never been a princess assigned a Shadow. And these two are keys in a prophecy to save the world from a dark and terrible god.
The premise is fairly simple and quite familiar, but the execution isn't just highly enjoyable, it is more than the description promises.
Not the least of which is because of Zariya. A fierce sixteen-year-old princess, Zariya is the king's favorite child, and is a cripple. She faces gods, travels seas, and stares down death. She does it on horseback, in slings, and through the use of her dual canes. She has a couple moments of self-pity because there are promises of a cure that never materializes, but she navigates the world with a sharp mind and an elemental gift. And she is physically desired (although nothing explicit or "devotee-like").
I held my breath every time the book spoke of a "cure". I was positive this would be a book that forced it onto our heroine. Too many books make the snide claim that crips can't save the world. Well, not this one! Sure, Zariya is just one part in the prophecy, but she plays a big one and does it well.
Khai is a Shadow unlike any before. Born in a girl's body, Khai is made an honorary boy for the purposes of training, though Khai isn't told about their birth sex until nearing puberty. Ultimately, Khai realizes they are both male and female. They are one of the best fighters in the world and are loyal.
While I didn't always enjoy the way the world around Khai tried to force them into a female role, I'm sure it rings true to certain people. The story is told through Khai's perspective.
The world is also populated with humans and mythical beings in a myriad of colors. Zariya and Khai both have brown skin.
Of course, representation means nothing if it isn't done well. It becomes intensely diminished if the story isn't entertaining. Good thing I found Starless a compelling and worthwhile read.