Vote goes to the Scarab Medallion. Reason: Strictly sentimental. =3 Not like any of those on the list are prolific defenders of Air anyway
It shows the lack of air counters under high level battling
I chose Earthen Codestone because it's cheap and can reflect a reasonable amount of air and even some dark. Double Dryer is good except that it's fragile and only blocks air. That's my opinion thanks for reading.