A yugioh question regarding Drastic Drop Off.?

Question

Can I use Drastic Drop Off on my opponent's draw phase?

Answer 1

Yes, this card can be activated immediately after your opponent adds any card from their deck to their hand, including drawing a card. Since it is a counter trap it can be activated during any step of your opponent's turn as long as the activation condition has been fulfilled, including the damage step. However, this card must be activate IMMEDIATELY after the card(s) is/are picked up. If any other effect takes place after the card is added to the opponent's hand this card cannot be activated. Say you activate Graceful Charity, you draw three cards and immediately discard 2 cards, so your opponenet would be unable to activate Drastic Drop Off.

Answer 2

You can use Drastic Dropoff whenever an opponent draws a card.  So you can use it whenever you want.  You can use it when your opponent draws during the draw phase, when they use Allure of Darkness or Solar Recharge, as well as anything else that allows them to draw cards.  Even monster cards that allow draws like Cyber Phoenix, Card Trooper, or Cyber Valley.  It's not just for drawing cards either.  You can activate it when your opponent uses any card that would add a card to their hand from their deck.  Cards such as the widely used Reinforcement of the Army, E-Hero Stratos, or Sangan.