At the beginning of you r second main phase, look at the top X cards of your library, where X is the total amount of life your opponent lost this turn. Exile one of those cards and put the rest on the bottom of your library in a random order. You may play the exile card this turn.
NM-Mint - $0.80
Lightly Played - $0.70
Moderately Played - $0.70
Heavily Played - $0.60
Damaged - $0.50
NM-Mint Non English - $0.80
Lightly Played Non English - $0.70
Moderately Played Non English - $0.70
Heavily Played Non English - $0.60
Damaged Non English - $0.50