At the beginning of your upkeep, put a time counter on The Moment.
,
: Untap target creature you control. 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.) until The Moment leaves the battlefield.
,
: Destroy each nonland permanent with mana value less than or equal to the number of time counters on The Moment. Then sacrifice The Moment. Activate only as a sorcery.