Visions of Phyrexia is a rare Enchantment card from Magic Online Promos (PRM), collector number 105742.
At the beginning of your upkeep, exile the top card of your library. You may play that card this turn. At the beginning of your end step, if you didn't play a card from exile this turn, create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")