DoOon Mode (The Mode Series)

DoOon Mode (The Mode Series) by Anthony, Piers. hardcover edition. ISBN: 9780312874636.

Beyond the world we know there is a multiverse of Modes where many strange realities interlock in an infinitely intricate pattern, and a perverse and deranged Emperor plays a deadly multidimensional game with human pawns as his slaves. Now, with DoOon Mode, Piers Anthony at last delivers the breathtaking climax to this awesome saga. Fearing the heroine Coleens dawning power, the depraved Emperor Ddwng dispatches a terrible Mind Monster to assault her soul and bend her to his will. To protect herself, and those she loves, Coleen must journey back through many worlds to her own home on Earth, face her deepest and darkest fears, and draw the strength for a final confrontation to save the multiverse from tyranny and domination.