You may choose an opponent with no cards in their graveyard. In that case, they will not get to return anything.
Skullwinder
The chosen opponent gets to choose which card to return from their graveyard to their hand.
Skullwinder's enters-the-battlefield ability targets only the card in your graveyard. If that card is an illegal target as the ability tries to resolve, the ability won't resolve and none of its effects will happen. No cards will be returned to any player's hand.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. James Paick
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
