Tengu format ruling
Light of Intervention
Card effect (current official text)While this card is on the field, Monster Cards cannot be Set or flipped face-down. If a Monster Card would be Set, it must be Normal Summoned in face-up Defense Position.
Rulings
- You can activate (flip face-up) this card at any time; it does not need to be activated in response to a Summon.
- The effect of this card applies to both players, and does not affect monsters that are already on the field face-down. These monsters remain face-down until flipped face-up as normal.
- While this card is on the field, monsters can be Normal Summoned in face-up Defense Position, and can be the target of Trap Hole and will trigger effects like the effect of Mysterious Puppeteer.
- While this card is on the field, if a monster would be Special Summoned in face-down Defense Position (such as with Cyber Jar or Nimble Momonga), it is instead Special Summoned in face-up Defense Position.
- While this card is on the field you cannot flip a monster face-down with Book of Moon, Darkness Approaches, etc.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.