Protecting Spirit

As an additional cost to cast this spell, you may sacrifice a creature and/or discard a card.
Flash
If you sacraficed a creature when you cast this spell, it gains "If an opponent would cause you to sacrifice a creature, instead they sacrifice a creature."
If you discarded a card when you cast this spell, it
gains "If an opponent would cause you to sacrifice a creature, instead they discard a card."
If you did both it gains indestructable.