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{T}: Add {C}. Spend this mana only to cast a face-down creature spell, pay a mana cost to turn a manifested creature face up, or pay a morph cost. (A megamorph cost is a morph cost.)
If a face-down creature with megamorph is turned face up some other way (for example, if you manifest a card with megamorph and then pay its mana cost to turn it face up), you won’t put a +1/+1 counter on it.
Megamorph is a variant of the morph ability. You can find more information on morph on cards with morph from the Khans of Tarkir set.
The mana produced by Qarsi Deceiver can’t be used to cast a spell that instructs you to manifest cards.
Turning a face-down creature with megamorph face up and putting a +1/+1 counter on it is a special action. It doesn’t use the stack and can’t be responded to.
