MArcomage

I think that that effect is not possible unless immediately after a swift or quick card

I think it's perfectly possible. It only has very limited use. (The only thing I can think of is retrieving a mage card for cards like Meditation. not even worth a common slot, Id say.)

Retrieving it should be possible, but negating the effect wouldn't be. That information wouldn't still be stored by the game following the opponent's turn, and you can't tell by looking at the card whether damage was dealt to tower or wall or if resource reductions had brought values below zero.

Ah, that kind of problems.

This card would be helpful after cards witch has a random aspect...