Gaunter O'Dimm

Upon playing tell a riddle (preferably GO'D's
riddle, available online).
All other players write down 3 guesses and reveal
them at the same time.
All who guess wrong must choose: Sacrifice a
creature or lose 5 life.
If at least one player doesn't answer correctly,
this card becomes indestructible.
If all answer correctly this card is exiled and the
owner draws 3 cards.