Windbreak, Uncommon 0-cost
Nature.
Stock:+2
If opponent's played or discarded an Aria card last round, negate the effects
I feel that this needs clarification.
First, I assume that the negation is the effects of the opponent's played card(s). How many of those effects, though? Tower and wall change to both players? Token gain/loss? Stock changes? Is the cost of the played card refunded? Are discarded cards returned to players' hands?
Typically, when a card negates effects, it specifies exactly which ones.
This becomes a lot more difficult due to the effect triggering if an Aria card is discarded. There are several cards that can cause entire hands to be discarded, and the way this is written, the effect occurs in those cases.
If you meant that the opponent either played an Aria or selected an Aria card for discard in place of playing a card (and not that any Aria was sent to either player's Graveyard), then it should read "If opponent's last card was Aria" which describes either case (and is how
Reuse the rubble operates). But even then, the specifics of the negation need to be made clear.