The immensely huge world Robert Jordan has created. It took me a bit to get used to the talk and lore of just the basics. Then you go on to think a Myyrdraal is like this ultimate enemy, to figure out a darkfriend can outmatch him, but then the seals are giving out and a forsaken is a beast.......I could go on like that for pages. And the One Power has to be the strongest sort of magic in a book there is, depending on the wielder. Because once you start learning how their flows work, you start realizing just how powerful they really are. And the various different tallents are always so awesome when a new one is introduced. And even the Darkfriend's tricks like raven and rat spies, darkhounds that even a drop of their saliva will kill painfully and too many more to name. All in all it has to be the most well thought out fantasy universe there is. Truly.