It's not one book, it's 47books, at about 250 pages each. I read 2-3 of them a day. Anyway, they might excist in english too, I think they have been translated and released in a number of languages. I think the character Vintersorg appears 4-5 times, and he's not very important, but his name is beautiful....
Thanks The Somberlain!
I'm kinda curious now... If someone wants to talk about this 'Vintersorg' character fell free to do it, and I'll be very grateful.