Unsettling Twins

Any time you have priority, you can turn a manifested permanent you control face up by revealing that it's a creature card (ignoring any copy effects or type-changing effects that might be applying to it) and paying its mana cost. This is a special action. It doesn't use the stack and can't be responded to.

If your library contains only one card when you manifest dread, you'll look at that card and put it onto the battlefield face down. You won't have the option to put it into your graveyard instead. If your library contains no cards when you manifest dread, you won't do anything.

Unlike a face-down creature that was cast using a disguise or morph ability, a manifested creature may still be turned face up after it loses its abilities if it's a creature card.