Fallen of Obsidian Twilight: Asi Magnor

From publisher blurb:

Sheathed in fragrant wrappings and armored by magic and sheer age, the undead emperor Asi Magnor conquered the world before, and after, his death. He radiates power and malevolence, the desire to rule and the power to clutch the world in his claw-like hands or crush it beneath his sandaled feet. Asi Magnor was born into a long and unbroken line of kings in the desert Kingdom of Shaan. The Shaan were known, before the cataclysm, as a peaceful and cosmopolitan people with ornate and elaborate death rituals, but in the time of Asi Magnor, some three thousand years before the cataclysm, they were a war-like people with advanced cities, agriculture and great command of magic.