Tengu format ruling
Firestorm Prominence
Card effect (current official text)When this card is destroyed by battle and sent to the Graveyard, destroy all face-down and non-FIRE monsters.
Rulings
source: Rulings_Tengu (Format Library) · 1 era-inappropriate line(s) removedRulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.