Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

"On a failed save, target creature becomes paralyzed."

Secret Lair Drop

The List

Double Masters

When Oubliette enters the battlefield, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Masters Edition

When Oubliette comes into play, remove target creature and all Auras attached to it from the game. Note the number and kind of counters that were on that creature.
When Oubliette leaves play, return the removed card to play under its owner's control tapped with the noted number and kind of counters on it. If you do, return the removed Aura cards to play under their owner's control attached to that permanent.

Arabian Nights

Select a creature in play when Oubliette is cast. That creature is considered out of play as long as Oubliette is in play. Hence the creature cannot be the target of spells and cannot receive damage, use special powers, attack, or defend. All counters and enchantments on the creature remain but are also out of play. If Oubliette is removed, creature returns to play tapped.

Any one-shot effects that are waiting “until [this] leaves the battlefield,” such as that of Kitesail Freebooter, won't happen when a permanent phases out.

Choices made for permanents as they entered the battlefield are remembered when they phase in.

A creature phased out by Oubliette doesn't phase in during its controller's untap step as normal. Rather, it phases in immediately after Oubliette leaves the battlefield.

Abilities that trigger when a creature becomes tapped won't trigger when the creature phases in tapped.

Any continuous effects with a “for as long as” duration such as that of Awakener Druid ignore phased-out objects. Any such effects will expire if their conditions are no longer met after ignoring the phased-out objects.

Each Aura and Equipment attached to a permanent that's phasing out also phases out. They will phase in with that permanent and still be attached to it. Similarly, permanents that phase out with counters phase in with those counters.

If Oubliette leaves the battlefield before its triggered ability resolves, the target creature won't be phased out or tapped.

Phasing out doesn't cause any “leaves the battlefield” abilities to trigger. Similarly, phasing in won't cause any “enters the battlefield” abilities to trigger.

While a permanent is phased out, it's treated as though it doesn't exist. It can't be the target of spells or abilities, its static abilities have no effect on the game, its triggered abilities can't trigger, it can't attack or block, and so on.