Primal Order

At the beginning of each player's upkeep, Primal Order deals damage to that player equal to the number of nonbasic lands they control.

Destructive Flow

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

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Thelonite Monk

{T}, Sacrifice a green creature: Target land becomes a Forest. (This effect lasts indefinitely.)

Razorlash Transmogrant

Razorlash Transmogrant can't block.
{4}{B}{B}: Return Razorlash Transmogrant from your graveyard to the battlefield with a +1/+1 counter on it. This ability costs {4} less to activate if an opponent controls four or more nonbasic lands.

Blood Moon

Spectrum Sentinel

Protection from multicolored (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything multicolored.)
Whenever a nonbasic land an opponent controls enters, you gain 1 life.

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Ashaya, Soul of the Wild

Ashaya, Soul of the Wild's power and toughness are each equal to the number of lands you control.
Nontoken creatures you control are Forest lands in addition to their other types. (They're still affected by summoning sickness.)

Wasteland

{T}: Add {C}.
{T}, Sacrifice Wasteland: Destroy target nonbasic land.

Magus of the Moon

Harmless Offering

Target opponent gains control of target permanent you control.

Burning Earth

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

Wilderness Elemental

Trample
Wilderness Elemental's power is equal to the number of nonbasic lands your opponents control.

Mercadia's Downfall

Each attacking creature gets +1/+0 until end of turn for each nonbasic land defending player controls.

Field of Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Weight of Spires

Weight of Spires deals damage to target creature equal to the number of nonbasic lands that creature's controller controls.

Price of Progress

Price of Progress deals damage to each player equal to twice the number of nonbasic lands that player controls.

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}