War's Toll

Whenever an opponent taps a land for mana, tap all lands that player controls.
If a creature an opponent controls attacks, all creatures that opponent controls attack if able.

Power Surge

At the beginning of each player's upkeep, Power Surge deals X damage to that player, where X is the number of untapped lands they controlled at the beginning of this turn.

Price of Glory

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

Waking the Trolls

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Destroy target land.
II — Put target land card from a graveyard onto the battlefield under your control.
III — Choose target opponent. If they control fewer lands than you, create a number of 4/4 green Troll Warrior creature tokens with trample equal to the difference.

Impending Disaster

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

Ramunap Excavator

Llanowar Elves

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Pillage

Destroy target artifact or land. It can't be regenerated.

Molten Rain

Destroy target land. If that land was nonbasic, Molten Rain deals 2 damage to the land's controller.

Burning Earth

Whenever a player taps a nonbasic land for mana, Burning Earth deals 1 damage to that player.

Belbe, Corrupted Observer

At the beginning of each postcombat main phase, the active player adds {C}{C} for each of your opponents who lost life this turn. (Damage causes loss of life.)

Bust

Boom

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

Boom // Bust

Elvish Mystic

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.

Tectonic Instability

Whenever a land enters, tap all lands its controller controls.

Yurlok of Scorch Thrash

Vigilance
A player losing unspent mana causes that player to lose that much life.
{1}, {T}: Each player adds {B}{R}{G}.

Heartbeat of Spring

Whenever a player taps a land for mana, that player adds one mana of any type that land produced.

Choking Sands

Destroy target non-Swamp land. If that land was nonbasic, Choking Sands deals 2 damage to the land's controller.

Rancid Earth

Destroy target land.
Threshold — If seven or more cards are in your graveyard, instead destroy that land and Rancid Earth deals 1 damage to each creature and each player.

Anara, Wolvid Familiar

During your turn, commanders you control have indestructible. (Effects that say "destroy" don't destroy them. A creature with indestructible can't be destroyed by damage.)
Partner (You can have two commanders if both have partner.)

Zhur-Taa Ancient

Stoneshaker Shaman

At the beginning of each player's end step, that player sacrifices an untapped land of their choice.

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Horizon Stone

If you would lose unspent mana, that mana becomes colorless instead.

Destructive Flow

At the beginning of each player's upkeep, that player sacrifices a nonbasic land of their choice.

Nightshade Harvester

Whenever a land an opponent controls enters, that player loses 1 life. Put a +1/+1 counter on Nightshade Harvester.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Overabundance

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and Overabundance deals 1 damage to the player.