Assured Destruction

Assured Destruction enters the battlefield with 3,
time counters. At the beginning of your end step
remove a time counter from Assured Destruction.
When Assured Destruction has 0, time counters
on it; Destroy each nonland permanent on the battlefield, then each player mills X cards and
may cast them this turn without paying their
mana costs.
If this card would be destroyed, instead remove
all time counters from it.