Haven't read any fantasy books to be honest, usually fiction about real world or novels about real happenings.
Storywise, I think Knaak is bound to certain previously existing lore and the upcoming games? That would limit the possibilities a bit I guess.
This does not apply to your argument about Uldyssians story or your soap opera though. I must agree that the "spells" or powers Uldyssian uses, are vague and would have been more interesting if they resembled some of the powers in Diablo 1 or 2. The whole story about Uldyssian can be seen as him learning the magic within, or growing with experience as a character, as in levelling up as an edyrem, and this aswell could have been more descriptive.
Mendeln has powers which are more familiar to the Diablo series, being the Necromancer student of Rathma/Trag'oul, which appeals to me the most(as many others on this forum aswell). For me partly because of the "dark aspects" of his actions, partly because his powers and deeds resemble those of the necromancer.
But I still really like the sin war story, as a series to explain how things came to pass and . . . it's ... diablo .. :cool:
Interesting .. can't really agree on the sin war being bad storywise. I can understand the writing style/language is not of your liking, as that is very subjective, as in everyone has their own tastes. But I have to say the depth of the story and the way, in my opinion, the sin war trilogy offers the backbone to the diablo universe (as opposed to fanfiction), I find it really good. I can't say much about the other books yet, but I'd guess if you don't like the sin war, the other books won't interest you much either.