You know what? I completely missed that it says only creatures and permanents.
I think this card fits nicely. Used for/against A) Neurotoxin, B) Bone Wall, C) Dimensional Shields, D) Sundials, E) Wings, F) other(different shields/spells, flood, etc.)
I don't see this question asked yet, so I'll ask:
What happens if there aren't any spaces left to place the cards? Are they discarded or not played?
I would guess so the latter, but if it was the former then malignant cell/flooding and this might be more interesting.