The Prince of Dreams by Curt Benjamin
It began when Llesho was seven, and the Harn invaded his family's mountain kingdom of Thebin. His guards slaughtered before his eyes, he was carried off and sold into slavery on Pearl Island, as far as he knew, the sole survivor of his royal family.
At fifteen, visited by the specter of his newly dead mentor, he learned that his brothers were still alive and had also been sold into slavery. And so began his quest to earn his freedom by becoming a successful gladiator, and then to travel the lands finding and rescuing his brothers so that together they might raise an army and win back their kingdom from the cruel and barbaric Harn.
But each success led Llesho into still greater peril, and even with the aid of two of his brothers, the trickster god himself, a young witch and her even more powerful father, several of his fellow gladiators, and the Emperor Shou, Llesho was not certain he would be able to reach his goal. Not when both the Harn and the evil Master Markko were set on his death, and not when the very gates of Heaven seemed to be shut against him. Only if Llesho could learn the truth about his own mysterious heritage and the powers locked inside him did he stand any chance of saving his own people and reopening the pathway between mortals and gods....