Shadows of the Past

Oracle Text

Whenever a creature dies, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

4B: Each opponent loses 2 life and you gain 2 life. Activate this ability only if there are four or more creature cards in your graveyard.

Card Rulings

6/22/2015 Once you legally activate the last ability, it doesn’t matter how many creature cards are in your graveyard as it resolves.