A rare card, "Mirror, Mirror" operates much like a traditional duplicate card, except for the price of 20 turns you get a chance to DOUBLE the number of one user selected card.
For example, you want to finish off a recently crapped upon MOW and need a lot of Master Craftsman cards. You could duplicate and buy packs until you had HALF the total amount you needed to undo this great injustice. You could then cast the "Mirror, Mirror" card on your MC stack until the double goes through.
Any balance issues could be fixed by lowering the 50% chance that a duplicate has to say maybe 20%, so really you'd need 5 rare "Mirror, Mirror" cards and 100 turns in our wounded MOW scenario. Another fun way would be 50% double, 30% fail, 20% you LOSE all cards you had in the stack:)
Any comments automatically bettered if you know what TV series had an episode this card is named after. No google cheating!!!