Ozma by Candace Robinson

A land to remake…

At Ozma’s birth, the witch, Mombi, abducted and cast a spell on her, turning the infant into a male. Only when Ozma broke the witch’s curse did she discover who she is–the True Queen of Oz. Her freedom is short-lived when the Wizard, hungry for her power, imprisons her in a dark, brutal world, cut off from Jack and her magic.
Jack, too, was stolen as a child, forced to toil as Mombi’s slave. When he believes his lover died, Jack loses himself to an array of companions, while plotting his escape from Mombi.
Once Ozma is returned to the Land of Oz by a savior’s magic, she seeks to reunite with Jack while vowing to kill the two fae who ruined their lives. However, neither Jack or Ozma are the same as they once were. They must put their heartache aside to journey across the unforgiving land to stop the Wizard and keep evil from sweeping over the territories.