Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Entertaining and thought-provoking

This series has the usual Piers Anthony Wit, but is a much more "serious" and thought-provoking read than the Xanth series (which I enjoyed in my teens, but found got too "child-like" to keep my attention when I got older).This series has more the 'dark' feel of Tolkien's classic "Lord of the Rings" series - but actually comes from a much more original angle - each book comes from a very unique perspective of a "mortal man" that is suddenly thrust into taking on the role of an "immortal" (such as Death or Fate or War), and serve certain "duties" in order to maintain the proper "order" of the world. Piers Anthony does a great job of making each "immortal" role convincing as well as the actions and reactions of the mortals suddenly finding themselves in these roles. Makes a person think about the balance of forces in life.