I am not sure if this was intentional or just simply overlooked. Fighting against a Top50 DarkAir Deck, I noticed that my enemy destroyed me with BoneWall just by having a boneyard and Firefly Queen (or its upgraded version, don't remember). I have a Fire deck with FireShield being my primary defense and Fahrenheit as my primary attack and a few dragons for when I get to them.
As the fight went on, I was doing no damage whatsoever. He would spawn Fireflies, which would die, generating both Skeletons and more BoneWalls. The skeletons would then die, generating even more bonewalls. By the time my weapon was doing around 50 damage, he had almost 30 BoneWalls blocking me.