Rulings

• 2016-09-20
  If you no longer control an artifact with the highest converted mana cost as Padeem's triggered ability resolves, you don't draw a card.
• 2016-09-20
  If you don't control an artifact with the highest converted mana cost as your upkeep begins, Padeem's second ability won't trigger. You can't cast an instant to destroy an opponent's artifact during your turn before your upkeep begins.
• 2016-09-20
  If an artifact has in its mana cost, X is considered to be 0.
• 2016-09-20
  The artifact you control has to have the highest converted mana cost only among artifacts on the battlefield, not among all permanents on the battlefield.
• 2016-09-20
  If you no longer control an artifact with the highest converted mana cost as Padeem’s triggered ability resolves, you don’t draw a card.
• 2016-09-20
  If you don’t control an artifact with the highest converted mana cost as your upkeep begins, Padeem’s second ability won’t trigger. You can’t cast an instant to destroy an opponent’s artifact during your turn before your upkeep begins.