Unfezant is so frail that it'll probably get one-shot by everything regardless of how many times its physical defense was lowered. Even if it does matter, you can just switch. Thus, I would go with super luck.
Note that if you're playing a format where Arceus, Kangaskhan, Staraptor, Diggersby, Swellow, or Stoutland are allowed, use one of those instead of Unfezant.
