When Phyrexian Devourer's power is 7 or greater, sacrifice it. Exile the top card of your library: Put X +1/+1 counters on Phyrexian Devourer, where X is the exiled card's mana value.
Near Mint - £11.80
Lightly Played - £10.00
Moderately Played - £8.30
Heavily Played - £5.90
Damaged - £3.60
Near Mint Non English - £11.80
Lightly Played Non English - £10.00
Moderately Played Non English - £8.30
Heavily Played Non English - £5.90
Damaged Non English - £3.60