Prison Realm

As an additional cost to cast Prison Realm, you
may pay {x}. X can't be 0.
Flash
When Prison Realm enters the battlefield, you
may exile target spell or creature. Put X time counters on the exiled card. If it doesn't have
suspend, it gains suspend. When Prison Realm
leaves the battlefield, the exiled card's owner
may cast that card without paying its mana cost.