Arvinox, the Mind Flail isn't a creature unless you control three or more permanents you don't own. At the beginning of your end step, exile the bottom card of each opponent's library face down. For as long as those cards remain exiled, you may look at them, you may cast permanent spells from among them, and you may spend mana as though it were mana of any color to cast those spells.
NM-Mint - $17.50
Lightly Played - $16.60
Moderately Played - $15.70
Heavily Played - $14.00
Damaged - $11.40
NM-Mint Non English - $17.50
Lightly Played Non English - $16.60
Moderately Played Non English - $15.70
Heavily Played Non English - $14.00
Damaged Non English - $11.40
Foil Prices
NM-Mint Foil - $17.40
Lightly Played Foil - $16.60
Moderately Played Foil - $15.70
Heavily Played Foil - $14.00
Damaged Foil - $11.40
NM-Mint Foil Non English - $17.40
Lightly Played Foil Non English - $16.60
Moderately Played Foil Non English - $15.70
Heavily Played Foil Non English - $14.00
Damaged Foil Non English - $11.40