Abhorrent Oculus

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 a double-faced card is manifested, it will be put onto the battlefield face down. While face down, it can't transform. If the front face of the card is a creature card, you can turn it face up by paying its mana cost. If you do, its front face will be up.

Abhorrent Oculus's additional cost must be paid even if it's cast "without paying its mana cost" or for any alternative cost.

Some cards in the Duskmourn release have abilities that trigger "whenever you manifest dread." In circumstances where you are instructed to manifest dread but can't perform some or all of the steps of manifesting dread (probably because your library has one or fewer cards in it), these abilities will still trigger.

If a manifested creature would have disguise or morph if it were face up, you may also turn it face up by paying its disguise or morph cost, as appropriate.

Turning a permanent face up or face down doesn't change whether that permanent is tapped or untapped.