The Last Guardian was a very anticipating read for me, Medivh is an iconic character and it very enigmatic and eccentric, i've always wanted to read up on his character and this book gave me the chance to. Sadly this book did disappoint me a little, though it was a great read, i felt a lot of it covered other characters, this novel is essentially the closest you will get to a warcraft 1 novel which is a good thing and despite seeing less of medivh than expected, it gave me a good insight on azeroth in it's early days and some background behind Warcraft: Orcs And Humans.
The main issue i had was the lack of development towards Medivh's insanity, it felt very abrupt and was lacking in consistency, for the most part Medivh only has a few outbursts (i only counted two for the whole book) which readers could easily be misinterpreted, thinking that he is just very sharp spoken rather than having multiple personalities. in fact he only has one personality and that is of an eccentric hermit with high intellect with a loner complex. I wish that they explored more of Medivh's alter ego but the book doesn't until the very end.
I also felt that a lot of the book took place in areas outside of Karazhan, Medivh's home, i think if the book focused more on Karazhan and Medivh it would have made for a more interesting novel.
The book does describe the surroundings well however and the other characters are likeable, Medivh is still a great character all round but he just didn't receive enough attention. Sadly most of the attention is driven towards Khadgar who is an excellent character in the Warcraft series, though i do like how Aaron Rosenberg portrays him more with his witty personality, He is still a great character in The Last Guardian. Others such as Lothar and Garona appear also though their main appearance is near the end of the book, i personally never really cared for any of these two characters though, Lothar is just too goody goody and Garona... well she's just a total bitch.
Overall i think The Last Guardian is rather lacking in the characters but in terms of the descriptions, it is rather deep, you will easily be able to portray an image of Karazhan after reading this book. I would personally recommend it as though it's characters (besides Khadgar) aren't really fleshed out, the descriptive writing is excellent. It could have been a lot better than it was though.
So if you're looking to read upon the events of Warcraft: Orcs and Humans and haven't played the game, give this book a read as it will give you a heads up. It was a good read overall.