Revenant's Storm (The Wicked West series)

Centuries into the future, the American southwest has returned to a lawless frontier. Glittering cities corrupt with gambling and prostitution hoard the wealth while shantytowns thirst and suffer. But the true danger lies with rumors of missing bodies and empty graves. Four lives twist together as a dark prophecy comes into fruition: a child sacrifice, a defected boy soldier, an immigrant scientist, and a charismatic sharpshooter each twist the fate of the handsome aristocrat in his endeavors to raise an army of the dead.