Horizon Stone

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

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Zhur-Taa Ancient

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

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.

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.

Manabarbs

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

Ribbons

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Each opponent loses X life.

Cut // Ribbons

Treacherous Terrain

Treacherous Terrain deals damage to each opponent equal to the number of lands that player controls.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Banefire

Banefire deals X damage to any target.
If X is 5 or more, this spell can't be countered and the damage can't be prevented.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Magus of the Vineyard

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

Swamp

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.

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.)

Spiteful Visions

At the beginning of each player's draw step, that player draws an additional card.
Whenever a player draws a card, Spiteful Visions deals 1 damage to that player.

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.

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.

Heartbeat of Spring

Zhur-Taa Druid

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

Forest

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}.

Immolation Shaman

Whenever an opponent activates an ability of an artifact, creature, or land that isn't a mana ability, Immolation Shaman deals 1 damage to that player.
{3}{R}{R}: Immolation Shaman gets +3/+3 and gains menace until end of turn.

Green Sun's Twilight

Reveal the top X plus one cards of your library. Choose a creature card and/or a land card from among them. Put those cards into your hand and the rest on the bottom of your library in a random order. If X is 5 or more, instead put the chosen cards onto the battlefield or into your hand and the rest on the bottom of your library in a random order.

Riveteers Charm

Choose one —
• Target opponent sacrifices a creature or planeswalker they control with the highest mana value among creatures and planeswalkers they control.
• Exile the top three cards of your library. Until your next end step, you may play those cards.
• Exile target player's graveyard.

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.

Enchantress's Presence

Whenever you cast an enchantment spell, draw a card.

Hull Breach

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Destroy target artifact and target enchantment.

Rootweaver Druid

When Rootweaver Druid enters, each opponent may search their library for up to three basic land cards. They each put one of those cards onto the battlefield tapped under your control and the rest onto the battlefield tapped under their control. Then each player who searched their library this way shuffles.

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.

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Theater of Horrors

At the beginning of your upkeep, exile the top card of your library.
During your turn, if an opponent lost life this turn, you may play lands and cast spells from among cards exiled with Theater of Horrors.
{3}{R}: Theater of Horrors deals 1 damage to target opponent or planeswalker.

Exsanguinate

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

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.)

Fireball

This spell costs {1} more to cast for each target beyond the first.
Fireball deals X damage divided evenly, rounded down, among any number of targets.

Read the Bones

Scry 2, then draw two cards. You lose 2 life. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Sign in Blood

Target player draws two cards and loses 2 life.

Mountain

Magus of the Candelabra

Rug of Smothering

Flying
Whenever a player casts a spell, they lose 1 life for each spell they've cast this turn.

Dig Up

Cleave {1}{B}{B}{G} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Search your library for a [basic land] card, [reveal it,] put it into your hand, then shuffle.

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.

Harrow

As an additional cost to cast this spell, sacrifice a land.
Search your library for up to two basic land cards, put them onto the battlefield, then shuffle.

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.)

Diabolic Revelation

Search your library for up to X cards, put those cards into your hand, then shuffle.

Apocalypse Hydra

Apocalypse Hydra enters with X +1/+1 counters on it. If X is 5 or more, it enters with an additional X +1/+1 counters on it.
{1}{R}, Remove a +1/+1 counter from Apocalypse Hydra: It deals 1 damage to any target.

Jaya's Immolating Inferno

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Jaya's Immolating Inferno deals X damage to each of up to three targets.

Fiery Emancipation

If a source you control would deal damage to a permanent or player, it deals triple that damage to that permanent or player instead.

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.

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.

Lavalanche

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

Stoneshaker Shaman

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

Xantcha, Sleeper Agent

Xantcha, Sleeper Agent enters under the control of an opponent of your choice.
Xantcha attacks each combat if able and can't attack its owner or planeswalkers its owner controls.
{3}: Xantcha's controller loses 2 life and you draw a card. Any player may activate this ability.

Damnable Pact

Target player draws X cards and loses X life.

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.

Putrefy

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

Dictate of Karametra

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

Rites of Flourishing

At the beginning of each player's draw step, that player draws an additional card.
Each player may play an additional land on each of their turns.

Xira Arien

Flying
{B}{R}{G}, {T}: Target player draws a card.

Terminate

Destroy target creature. It can't be regenerated.

Tectonic Instability

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

Nightshade Harvester

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

Mana Flare

Umbral Mantle

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

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}.

Return to Nature

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Exile target card from a graveyard.

Regrowth

Return target card from your graveyard to your hand.

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

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.