When Contagion Engine enters the battlefield, put a -1/-1 counter on each creature target player controls. {4}, {T}: Proliferate, then proliferate again. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)
NM-Mint Foil - $47.30
Lightly Played Foil - $42.60
Moderately Played Foil - $37.90
Heavily Played Foil - $33.20
Damaged Foil - $23.70
NM-Mint Foil Non English - $47.30
Lightly Played Foil Non English - $42.60
Moderately Played Foil Non English - $37.90
Heavily Played Foil Non English - $33.20
Damaged Foil Non English - $23.70