Fraying Sanity

Oracle Text

Enchant player

At the beginning of each end step, enchanted player puts the top X cards of his or her library into his or her graveyard, where X is the number of cards put into that graveyard from anywhere this turn.

Card Rulings

7/14/2017 Fraying Sanity’s triggered ability counts the number of cards that were put into the enchanted player’s graveyard during the turn, even if Fraying Sanity wasn’t on the battlefield at the time those cards were put there, and even if those cards have left that graveyard.
7/14/2017 The value of X is determined only as Fraying Sanity’s triggered ability resolves. For example, if three Fraying Sanity Auras are attached to one player who had four cards put into his or her graveyard this turn, X will be four for the first ability to resolve, eight for the second, and sixteen for the third.