As long as this card remains face-up on the field, both players must turn their respective Decks upside down and proceed with the current Duel.
Rulings
Individual Card FAQs
When this card's effect is active, both Decks are flipped upside down, and now the face of the top card of the Deck is showing.
If a card effect requires a player to shuffle their Deck, it is shuffled and cut face-down so the cards are not seen, and then placed face-up in the Deck Zone.
If a "Parasite Paracide" is face-up in your Deck before this card is activated, it will become face-down once this card is active. Its effect will still activate when it is drawn.
If 2 copies of "Convulsion of Nature" are active, the Decks are still upside-down (they do not revert to normal).
Netrep Rulings
Cards that are turned face-up in the deck will be drawn face-down while โConvulsion of Natureโ is active, but still will resolve properly.