Pernicious Deed

Oracle Text

X, Sacrifice Pernicious Deed: Destroy each artifact, creature, and enchantment with converted mana cost X or less.

Card Rulings

3/16/2018 If a permanent has in its mana cost, X is considered to be 0.
3/16/2018 A token has a converted mana cost of 0 unless it is copying something else.