Have to agree with
UglyBastard here on pretty much every point. (responding to his earlier post, the post above this was written while I was writing this one, lol)
Would like to point out that the spells for Nefarian are "From your opponent's class" which, honestly, makes it even worse imo. If you're facing, say, Warlock, there's now a really decent chance of getting something actually useless like Sense Demons / Sacrificial Pact, and on top of that you also have a chance of getting something very unimpactful like mortal coil. You can run into a similar situation with rogue, getting something literally useless like deadly poison / oil or a very low impact backstab (a good card in itself, but for 9 mana you want spells that make it worth) - same deal with Hunter and its beast cards and Warrior with the armor related cards.
The fact that he's below the curve for 9 mana just makes it even sadder. Honestly think Nefaran is just garbage. At least Ysera is very durable AND every dream card is incredibly strong AND she dodges BGH.
I think Drakanoid crusher is p. strong really, but, unless you're going to run the other dragon synergy cards he isn't really worth the slot in constructed. He's very very good for Arena.
Also agree that Volcanic Drake is the most interesting, but the fact that he only has 4 HP is pretty rough. Best use for Drake would be something where you Fan of Knives a bunch of silver hand recruits, then play him for like 1 mana... but I don't think it's consistent enough to be worth it unless you need a critical mass of dragons in your deck.
All in all, still not convinced to buy the adventure