Of the five women pictured, only the center model is showing actual ass, and then merely 3/4 of it. The woman on the bottom right is actually displaying her anus, but not really her ass. It is generous, therefore, to say that this boxcover of this ass-based title shows a paltry 40 percent ass.
You will agree that anus and ass are not the same thing. That is why the anus is known as the ass hole. The ass, or butt, is the fleshy cushion that protects the anus. This has been known for centuries and I needn't remind you. I think it was in "The Da Vinci Code".
I am left to conclude that "Butt Blasted" means that most of these poor Brazilian women's asses have been blasted off.
See also: Mercenary Pictures