, : Target opponent chooses one of the top two cards of your graveyard. Exile that card and put the other one into your hand.
It does not target the cards, but it targets the opponent. If you can’t target an opponent, you can’t activate this ability.
If there is only one card in your graveyard, it is exiled by the first part of the effect and you do not get to put any cards into your hand since the second part fails.
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: Target opponent chooses one of the top two cards of your graveyard.