Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each unspent green mana you have.

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Sword of the Paruns

As long as equipped creature is tapped, tapped creatures you control get +2/+0.
As long as equipped creature is untapped, untapped creatures you control get +0/+2.
{3}: You may tap or untap equipped creature.
Equip {3}

Exsanguinate

Each opponent loses X life. You gain life equal to the life lost this way.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Helix Pinnacle

Shroud (This enchantment can't be the target of spells or abilities.)
{X}: Put X tower counters on Helix Pinnacle.
At the beginning of your upkeep, if there are 100 or more tower counters on Helix Pinnacle, you win the game.

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.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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.)

Manabarbs

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

Burning Earth

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

Swamp

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.

Veteran Explorer

When Veteran Explorer dies, each player may search their library for up to two basic land cards, put them onto the battlefield, then shuffle.

Platinum Emperion

Your life total can't change. (You can't gain or lose life. You can't pay any amount of life except 0.)

Instill Energy

Enchant creature
Enchanted creature can attack as though it had haste.
{0}: Untap enchanted creature. Activate only during your turn and only once each turn.

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Golgari Signet

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Dictate of Karametra

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

Zhur-Taa Druid

{T}: Add {G}.
Whenever you tap Zhur-Taa Druid for mana, it deals 1 damage to each opponent.

Leyline Tyrant

Flying
You don't lose unspent red mana as steps and phases end.
When Leyline Tyrant dies, you may pay any amount of {R}. When you do, it deals that much damage to any target.

Sol Ring

Eladamri's Vineyard

At the beginning of each player's first main phase, that player adds {G}{G}.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Birds of Paradise

Shizuko, Caller of Autumn

At the beginning of each player's upkeep, that player adds {G}{G}{G}. Until end of turn, they don't lose this mana as steps and phases end.

Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Lair of the Hydra

If you control two or more other lands, Lair of the Hydra enters tapped.
{T}: Add {G}.
{X}{G}: Until end of turn, Lair of the Hydra becomes an X/X green Hydra creature. It's still a land. X can't be 0.

Lavalanche

Lavalanche deals X damage to target player or planeswalker and each creature that player or that planeswalker's controller controls.

Arcane Signet

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Gruul Signet

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

In Garruk's Wake

Destroy all creatures you don't control and all planeswalkers you don't control.

Klothys, God of Destiny

Indestructible
As long as your devotion to red and green is less than seven, Klothys isn't a creature.
At the beginning of your first main phase, exile target card from a graveyard. If it was a land card, add {R} or {G}. Otherwise, you gain 2 life and Klothys deals 2 damage to each opponent.

Mountain

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.

Court of Ire

When Court of Ire enters, you become the monarch.
At the beginning of your upkeep, Court of Ire deals 2 damage to any target. If you're the monarch, it deals 7 damage instead.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Magus of the Vineyard

Crackle with Power

Crackle with Power deals five times X damage to each of up to X targets.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Windgrace's Judgment

For any number of opponents, destroy target nonland permanent that player controls.

Kaervek the Merciless

Whenever an opponent casts a spell, Kaervek the Merciless deals damage equal to that spell's mana value to any target.

Seedborn Muse

Untap all permanents you control during each other player's untap step.

Mana Flare

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.

Painful Quandary

Whenever an opponent casts a spell, that player loses 5 life unless they discard a card.

Zo-Zu the Punisher

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

Forest

Rakdos Signet

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.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Plague Wind

Destroy all creatures you don't control. They can't be regenerated.

Soul Shatter

Each opponent sacrifices a creature or planeswalker with the highest mana value among creatures and planeswalkers they control.

Wound Reflection

At the beginning of each end step, each opponent loses life equal to the life they lost this turn. (Damage causes loss of life.)

Tectonic Instability

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

Mana Web

Whenever a land an opponent controls is tapped for mana, tap all lands that player controls that could produce any type of mana that land could produce.

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.

Staff of Domination

{1}: Untap Staff of Domination.
{2}, {T}: You gain 1 life.
{3}, {T}: Untap target creature.
{4}, {T}: Tap target creature.
{5}, {T}: Draw a card.

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.

Stoneshaker Shaman

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

Llanowar Elves

Keeper of Progenitus

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