"The new prototype utilizing a rotational axis is marvelously effective: it makes me want to tear my own ears off."
—Ashnod, to her assistants

Keening Stone

{5}, {T}: Target player mills X cards, where X is the number of cards in that player's graveyard.

As it spins, dead voices shriek in an ever-increasing cacophony, rending the mind asunder.

The Brothers' War Retro Artifacts

Commander 2016

{5}, {T}: Target player puts the top X cards of his or her library into his or her graveyard, where X is the number of cards in that player's graveyard.

Rise of the Eldrazi

The value of X is determined as the ability starts to resolve. If the targeted player has five cards in their graveyard at that time, for example, this ability will put five more cards into that graveyard from the top of that player's library.