Gateway

Draw 5 cards and put them in a pile face-up; at
any time your opponents may play the top card
and may spend any type of mana to cast it. Draw
5 cards and put them in a pile face-down; once a
turn you may pay 2 Life to draw the top card.
When either pile is gone, exile Gateway and you
choose one: Gain 10 Life, or search your library,
graveyard and all permanents in play for Emissary
of Dragon, remove it from the game and then put
it into play under your control.