The rules for Steel Hellkite say any nonland permanent with converted mana cost X gets destroyed if I deal combat damage this turn. The second ruling states "It doesn't matter who controlled those permanents at the time Steel Hellkite dealt combat damage, or if those permanents were even on the battlefield at that time."
Does this mean if I make the X cost 2/2, all my opponent's 2/2 cards, even in his library are destroyed?