King of Jokers

{b}{t}: Choose 2 cards at random from any
opponent's library. Show that opponent the 2
cards with one face down and the other face up.
That opponent chooses one. The chosen card
goes in opponent's hand. Reveal the other card
and put it in your hand. you may spend mana as
though it were mana of any type to cast it while
King of Jokers remains on the battlefield.
"Wanna know how I got this smile?"