MArcomage

Acid rain, Common 1gem
Destruction.
Enemy tower: -1
Enemy wall: -1
Discards a common Nature or Unliving in opponent's hand


The problem with this card is that, at one gem, it makes it too easy to trigger the Destruction keyword. If it's going to be Destruction, it needs to be more expensive. It's otherwise fine without the keyword.

Would the ease become an issue? Tremors only costs one more, you wouldn't play an Uncommon or Rare Destruction card unless you were sure you could play another to follow regardless(Edit: when you intend to trigger Dark Fury in any case), and there aren't any Quick or Swift Destruction cards to trigger the effect in one turn. The only situation I can see where such a small price difference would matter is when your Magic is reduced to one against a Brigand deck. Do you have any more in mind?o.o