Robert Silverberg 
Majipoor Chronicles 

Come to Majipoor, the magnificent, exotic planet of LORD VALENTINE’S CASTLE. Come with Hissune, favourite of Lord Valentine, as he probes the deepest secrets of Majipoor’s long past in the depths of the great Labyrinth.Join Hissune as he becomes one with its many peoples – dukes and generals, thieves and murderers, Ghayrogs and Metamorphs – and discovers wonder, terror, longing and love, and learns the wisdom that will shape his destiny.(First published 1982)