Sending all cards in the hand and on the field to the Graveyard is a cost. If there are no cards in your hand or on the field you cannot activate this card. You must have a card either in your hand or on the field to activate this card.
Netrep Q&As:
Q: If I activate “Reversal Quiz” with a “Black Pendant” on the field, does the damage from “Black Pendant” occur before or after our Life Points are exchanged?
A: After. Curtis Schultz, 04/04/2004