Rie's a rather haughty being, thinking of humans as short-lived creatures with very little understanding of the world around them. The world of the Nightmare Tree is so much more flexible and interesting than the world of linear-time that the humans live in! He hoards magical objects and books, piling them up in his cave, and his kingdom is a classic fantasy forest with wide sweeping meadows and a huge mountain in which Rie makes his home in a cave.

He's very carnivorous and hates vegetables, but loves tearing the heads off gummy bears. Sweets in general are one of his weaknesses though he has to transform into his human form to properly enjoy them. His dragon tastebuds aren't the best for picking up on the subtleties of sweet flavoring. His occasional attempts at baking never turn out well but Rie is difficult to dissaude from a task once he has his mind set on it.

As far as Rie is concerned, dragons are superior to all other Stygian subspecies. He will be polite to the other Stygians, of course, but a little aloof.