Think of the following situations (with no cards in hand):
Brainstorm. Wow, so now I can play with 5 Ancestral Recalls?!
Bazaar of Baghdad. Tap: Draw two cards
Timetwister/Wheel of Fortune/Time Spiral. Wow. So you get to play with 7 new cards until end of turn, while your opponent's cards are practically useless? Not to mention that your opponent needs to discard his/her hand for 7 cards that they will lose at end of turn. Wow, as if draw-7s weren't already broken enough...
+much much more!

Once this card finds its place, I can see it being broken...
Standby for an Abusian Mask tourny-winning decklist

And if you have any deck ideas for an engine/backbone of an Abusian Mask deck, post here/let me know.