When this card declares an attack, or if your opponent activates a monster effect (except during the Damage Step): You can excavate up to 5 cards from the top of your opponent's Deck, banish 1 excavated card, face-down, and place the rest on the top of the Deck in the same order
If you were holding the real card, the background of the image would be shiny and the little star patterns would change and move as you moved the card
It will correct 15-25% when it rotates out of Standard format
You can think of this kind of like the difference between a set of polygons and the bumpmap that goes on top of it, if you're familiar with 3D animation at all
As of now, some of the top decks in the format range between 50 and 70 dollars in minimum rarity, which is something that, I assure you, has not always been like that