Yu-Gi-Oh Card: Tragedy
Available from these partners:
Type:Normal Trap
Text:You can only activate this card when a monster on your opponent's side of the field in face-up Attack Position is changed to face-up Defense Position. Destroy all Defense Position monsters on your opponent's side of the field.
Printings: Dark Revelations Volume 3 (DR3-EN109)
Rise of Destiny (RDS-EN049)
Yugi's Legendary Decks: Yugi Battle City Deck (YGLD-ENB40)