Tengu format ruling
Radiant Mirror Force
Card effect (current official text)When an opponent's monster declares an attack while they control 3 or more Attack Position monsters: Destroy all Attack Position monsters your opponent controls.
Rulings
- If the number of face-up Attack Position monsters becomes 2 or less due to an effect chained to this card, all face-up Attack Position monsters your opponent controls are still destroyed when this card resolves.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.