Keldon Firebombers

When Keldon Firebombers enters, each player sacrifices all lands they control except for three.

Mechanized Warfare

If a red or artifact source you control would deal damage to an opponent or a permanent an opponent controls, it deals that much damage plus 1 instead.

Blood Moon

Magus of the Moon

Worldfire

Exile all permanents. Exile all cards from all hands and graveyards. Each player's life total becomes 1.

Shock

Decree of Annihilation

Exile all artifacts, creatures, and lands from the battlefield, all cards from all graveyards, and all cards from all hands.
Cycling {5}{R}{R} ({5}{R}{R}, Discard this card: Draw a card.)
When you cycle Decree of Annihilation, destroy all lands.

City on Fire

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
If a source you control would deal damage to a permanent or player, it deals triple that damage instead.

Apocalypse

Exile all permanents. You discard your hand.

Ragavan, Nimble Pilferer

Whenever Ragavan, Nimble Pilferer deals combat damage to a player, create a Treasure token and exile the top card of that player's library. Until end of turn, you may cast that card.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Jokulhaups

Destroy all artifacts, creatures, and lands. They can't be regenerated.

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Boil

Devastation

Omen of Fire

Return all Islands to their owners' hands. Each player sacrifices a Plains or a white permanent of their choice for each white permanent they control.

Mountain

Wake of Destruction

Destroy target land and all other lands with the same name as that land.

Ruination

Boiling Seas

Winds of Change

Each player shuffles the cards from their hand into their library, then draws that many cards.

Smoke

Players can't untap more than one creature during their untap steps.

Wildfire

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