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.
The first sentence of this card is a maintenance cost, not an effect. It does not start a Chain.
LIGHT and DARK monsters cannot be Special Summoned, face-up or face-down, while "Koa'ki Meiru Drago" is on the field.