Tomb of the Serpent Lord

Publisher's blurb:

There was once a powerful mage whose skill with the arcane arts attracted a small cult of followers, seeking to learn his mystical secrets. In an attempt to stave off death, the mage delved into dark magics, trapping his soul in his aging flesh. His followers entombed his brittle body in stone and sand. They laid traps and bound creatures to ensure his safety while they sought a means to return him to true life. One by one, his followers grew old and died, leaving none who yet remembered what was buried beneath the sands.