Emrakul, the Harvest's End

Emerge {8}{b/g}{b/g}{b/g}
Flying, trample, protection from green and
from white
Whenever Emrakul, the Harvest's End attacks,
defending player sacrifices all Food they control.
If three or more Food permanents were
sacrificed this way, prevent all damage Emrakul
would deal this turn. Otherwise, defending
player discards three cards unless they sacrifice
three permanents.