Forbidden Knowledge

Right off the bat, a cost of 8 makes this card hard to play, and most likely will have been set as a resource by the time you’re ready to use it.  That is, unless you speed up your resource drops. 

Both factions can use Onyxia’s scale.  But the Alliance also has Nightbloom available to build extra resources.  Once you’re up to 8, and activate forbidden knowledge, your round becomes an open book test.  Ideally, you could grab whatever you want with each draw, including your quest and other effect draws.  Great, right?  Except for one thing…what if your opponent destroys Forbidden knowledge?  Do you just lose, for not having a deck to draw from?  Or does your deck return to play?  In either case, it seems like a lot of trouble to go through for nothing.

Sealed: 1.0 – By the time you can use it, you might just be dead.  And there probably won’t be a clutch card in your deck to save you in sealed.

Constructed: 2.0 – I love it, in theory, but how many open book draws could you really hope to get before Forbidden Knowledge was destroyed?

Lazy Peon: 0.0 – No Rare cards allowed.

Raid: 1.0 – Yes, I could see a hero building up the resources for this, while the Onyxia player eats the team’s Priest or Shaman.  But then the dragon would eat it Forbidden Knowledge, too.