Brandon Sanderson's White Sand Omnibus

"On the planet of Taldain, the legendary Sand Masters harness arcane powers to manipulate sand in spectacular ways. But when they are slaughtered in a sinister conspiracy, the weakest of their number, Kenton, believes himself to be the only survivor. With enemies closing in on all sides, Kenton forges an unlikely partnership with Khriss--a mysterious Darksider who hi des secrets of her own. Assassins are coming for them from all directions, and Kenton's only true ally is Khriss, a visitor from the other side of the planet who has an agenda of her own to pursue"--