Wildfire

Each player sacrifices four lands. Wildfire deals 4 damage to each creature.

Boom

Destroy target land you control and target land you don't control.

At the beginning of your upkeep, if there are seven or more lands on the battlefield, sacrifice Impending Disaster and destroy all lands.

Destroy all lands or all creatures. Creatures destroyed this way can't be regenerated.

Lands don't untap during their controllers' untap steps.
At the beginning of each player's upkeep, that player untaps a land they control.

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Target player sacrifices a land.
Threshold — Each player sacrifices all lands they control instead if seven or more cards are in your graveyard.