Ok, I'm completely blown away by how terrible this card... appears... to be.
Either I'm I not getting it, or this card is just plain poor. A 3 cost card that removes all 0 or 1 cost cards. Maybe if it removed 2 cost cards as well it might nudge into the realm of usability, but for the most nobody has 0 to 1 cost cards that remain on the board for very long... The AI doesn't use them much that's for sure.
Blown away does have some utility as a foil for some strategies revolving around low cost cards -- e.g systematically destroying summoned bats with blood orb, or fueling inferno with cave rats and kobos while it destroys good cards of the opponent. Or, as the goblin hints, clearing out hordes of summoned kobos.
Another feature that could be overlooked is its ability to affect all cards. Goody bye to nasty overworld elixirs, tide callers, dreadmarsh plagues, unnatural gas traps, burning blood, wall of webs, etc.
I admit I would never buy it at cast 3, but I have lost enough games to tide callers and overworld elixirs alone that for two power cost, I just might carry it -- if I can only get an air deck that works!
In the next version it will affect only the opponent's cards.
The issue I had with it was : Air-based decks often have lots of cheaper stuff in them to bring up the speed, which I then don't want being "Blown Away" thank you very much.