Astaz Nimix, Emotional Oracle

Pay X life and reveal the top card of your
library: If the revealed card has converted
mana cost X or less, cast that card without
paying its mana cost. Otherwise, put that card
into your graveyard and each opponent loses
X life. Activate this ability only once each
turn.
You may cast cards in your graveyard with
converted mana cost less than the amount of
life you lost this turn.