Extinction Event

When this enters the battlefield destory all
creatures and each player sacrifices 3 lands.
All creatures have -3/-3, at the beginning of each upkeep each player takes 1 damage, at the
beginning of your end step add a regrowth
counter, when Extinction Event has 3 regrowth counters sacrifice Extinction Event,
Extinction Event's controller returns 3 target creatures and lands from their graveyard to the battlefield.