Advanced format ruling
Big Burn
Card effect (current official text)You can only activate this card when your opponent activates a card that targets a monster in the Graveyard. Remove from play all monsters in both players' Graveyards.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.