None of the Fantastique's you've encountered know the origin of the City of the Mad Sorcerer, however it's place in this pocket of the Beyond calls out to them; drawing them home. An ever-rotating cube containing a multitude of different environments, at its center is the seat of power for the current holder of the title of Fantastico.
Many have attempted to break into the City throughout the centuries but very few have lived to tell the tale, and even fewer have made it to the center.