As an additional cost to cast this spell, sacrifice a creature.

Search your library for a card, put that card into your hand, then shuffle.

Whenever a spell or ability an opponent controls causes you to discard cards this turn, return those cards from your graveyard to your hand.

When a spell or ability an opponent controls causes you to discard this card, return this card from your graveyard to your hand at the beginning of the next end step.