Isaac, Spared by God

When Isaac enters the battlefield, you and target
opponent each search your library for a creature
with mana cost less than or equal to triple the
number of times you have cast him from your
command zone. Shuffle the two cards, then exile
both facedown. The opponent looks at them and
tells you the names of both cards, but they may
lie. Select one and cast it without paying its costs.
Once per turn, if you would sacrifice Isaac, create
a 0/1 goat token. Sacrifice it Instead.