You may choose not to untap The Pandorica during your untap step.
,
: Untap another target nonland permanent, then it
phases out (While it's phased out, it's treated as though it doesn't exist. It phases in before you untap during your next untap step.). It can't phase in for as long as The Pandorica remains tapped. When The Pandorica becomes untapped or leaves the battlefield, that permanent phases in. Activate only as a sorcery.