Cthulhu, Abyssal God

Flying, Indestructible

As long as Cthulhu, Abyssal God is in your hand, creatures you control have "Sacrifice this creature:
reduce the converted mana cost of Cthulhu, Abyssal
God by {1}or by the mana color of the sacrificed
creature."

If Cthulhu, Abyssal God would leave play, you may
place him into your library four cards from the top.