The Bastard's Pearl

When Sheyn, a headstrong young aristocrat, disobeys his parents and travels to the far east, he passes through Kandaar, an isolated country of strange customs. He is abducted, transformed by a mysterious ritual, and sold to a barbarian king as a pleasure slave. When the king is killed by Kashyan the Bastard, dispossessed prince of Clan Savaan, Sheyn becomes Kashyan’s possession.
The Bastard expects Sheyn—now called Pearl—to behave as an obedient pleasure slave, but compliance is not in Sheyn’s nature. Nor does Sheyn's ordeal stop at being held captive by people he considers savages. The Red Temple covets Sheyn as a living gateway to the demon realm and plans to use him to summon the God of Death.
Kashyan loathes Sheyn, and Sheyn despises Kashyan, but when the Red Temple kidnaps Sheyn, honor compels Kashyan to rescue his slave, and he starts a war in the process. If they hope to stop the Red Monks from bringing hell to earth, Sheyn will have to accept Kashyan is more than an uncivilized brute, and Kashyan will have to admit there’s more to his Pearl than a pretty, arrogant exterior.