There are not many stories in mainstream fiction that feature a eunuch as the hero - a miniscule percentage in fact.
There are a few:
* The 'John the Eunuch' series, which are more detective stories than they are about John, the Eunuch, though we are allowed some intriguing glimpses into his character now and then.
* Anne Rice, 'Cry to Heaven.' A story about an Italian Castrato. Very good.
* Mary Renault, 'The Persian Boy.'
* Wilbur Smith, 'River God,' though there is no way that his eunuch, Taita, could possibly have mastered all the different skills he is said to be brilliant at.
Maybe two others.
And then there is mine. 'Not a Man' is the only full length novel that I know that is set in modern times, and features a eunuch as the main character. It is a Coming of Age story, the journey as Shuki rises from his lowly position as a bed-boy, an 'offense to Allah,' to become a person to be respected. The journey is not easy, but Shuki achieves his goal - to be a person to be respected, even though not a man.
To buy, look for 'Not a Man' by M. A. McRae, available from most online booksellers, either as an ebook, for $2.99, or as a paperback for around $20. 'Not a Man' is a full size novel of over 500 pages. It has been very well reviewed.
Excerpt from a review by Harper Collins: ‘Not a Man’ is an ambitious and insightful novel; it tells the story of Shuki, a young boy from the slums of Elbarada, a fictional area of Arabia, who is castrated against his will at the age of 10. Shuki’s journey is one of great trial but also incredible strength, courage, and determination, and as a hero, he is fantastic, evoking not only sympathy, but aspiration and reverence. I loved the fact that the operation which is supposed to prevent him from reaching manhood is the very thing that makes him strong and mature. The novel is written in a pared down manner; the narrative reminded me of the prose styling of Paulo Coelho: unaffected and matter-of-fact.