Definitely Darkness.
Lol, this isn't too bad against mindless, boring, and straight-forward decks (like rushes). So while it is an interesting little card, it kind of steers the meta-game in the wrong direction.
As for the mechanic, I'd much rather it be "..can no long identify cards not played..." or something of similar wording. What I'm trying to get at is that he shouldn't be able to see what he draws or see what cards you play (synergy with Cloak ftw). Also, I'd rather the white "able to be played" bars not be shown so that it would be even harder to identify the cards you have. Not because I'm a sadist, but because I obtain enjoyment from torturing others.
