Tengu format ruling
Koa'ki Meiru Drago
Card effect (current official text)During each of your End Phases, destroy this card unless you send 1 "Iron Core of Koa'ki Meiru" from your hand to the Graveyard or reveal 1 Dragon-Type monster in your hand. Neither player can Special Summon LIGHT or DARK monsters.
Rulings
- While the ① is applying, "Future Fusion" cannot be activated unless a non-LIGHT/DARK is revealed from the Extra Deck.
- While the ① is applying, "Future Fusion" cannot Special Summon a LIGHT-DARK monster during the second Standby Phase. In this case, the Fusion Monster will never be Special Summoned (it will not "try again" the next Standby Phase).
- The Ⓜ is a Maintenance Cost. It does not activate, and cannot be negated.
- If Iron Core cannot be sent to the GY (EG if "Dimensional Fissure" is applying), and no Dragon can be revealed, this card is destroyed.
- If "Mind on Air" is applying, you can't reveal a Dragon, so you must send an Iron Core to the GY or else destroy this card.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Tengu forum — sourced change requests get reviewed.