Gravekeeper's Ambusher (LVAL-EN032) [Legacy of the Valiant]

When this card is flipped face-up: You can target 1 card in your opponent's Graveyard; place that target on the bottom of their Deck. If this card is sent from the field to the Graveyard after being flipped face-up: You can target 1 "Necrovalley" card in your Graveyard; add that target to your hand. This card's effects cannot be negated by the effect of "Necrovalley".