You must ensure that your face-down spells and permanents can easily be differentiated from each other. You're not allowed to mix up the cards that represent them on the battlefield in order to confuse other players. The order they entered the battlefield should remain clear. Common methods for doing this include using markers or dice, or simply placing them in order on the battlefield.
Sage-Eye Harrier
Because the permanent is on the battlefield both before and after it's turned face up, turning a permanent face up doesn't cause any enters-the-battlefield abilities to trigger.
Morph lets you cast a card face down by paying {3}, and lets you turn the face-down permanent face up any time you have priority by paying its morph cost.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Chase Stone
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
