Geisha charm

Enchante : creature.
The enchanted creature is tapped and it don't
untap during player untap step.
At the end of the enchanted creature's
controller's turn, the owner of "Geisha Charm" reveals 2 cards from the top of his library, this
player can play a card with a converted mana cost less than or equal to that of the enchanted creature
without paying its mana cost. Then the
remaining cards goes to the graveyard.