Bloodletter of Aclazotz

Flying
If an opponent would lose life during your turn, they lose twice that much life instead. (Damage causes loss of life.)

Nesting Dragon

Flying
Landfall — Whenever a land enters the battlefield under your control, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature gets +1/+0 until end of turn.'"

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.

Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

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.

Exocrine

Ravenous (This creature enters the battlefield with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Bio-plasmic Barrage — When Exocrine enters the battlefield, it deals X damage to each player and each other creature.

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Forest

Apocalypse Hydra

Apocalypse Hydra enters the battlefield with X +1/+1 counters on it. If X is 5 or more, it enters the battlefield 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.

Rootbound Crag

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters the battlefield tapped unless you control two or more basic lands.

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.

Evolution Sage

Landfall — Whenever a land enters the battlefield under your control, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

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.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Zhur-Taa Ancient

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

Hydra Broodmaster

{X}{X}{G}: Monstrosity X. (If this creature isn't monstrous, put X +1/+1 counters on it and it becomes monstrous.)
When Hydra Broodmaster becomes monstrous, create X X/X green Hydra creature tokens.

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.

Belbe, Corrupted Observer

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

Fellwar Stone

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

Heartbeat of Spring

Damnable Pact

Target player draws X cards and loses X life.

Dragon Egg

Defender
When this creature dies, create a 2/2 red Dragon creature token with flying and "{R}: This creature gets +1/+0 until end of turn."

Hydra

Courser of Kruphix

Play with the top card of your library revealed.
You may play lands from the top of your library.
Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Exsanguinate

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

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.

Rockfall Vale

Rockfall Vale enters the battlefield tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Eladamri's Vineyard

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

Mountain

Spectral Searchlight

{T}: Choose a player. That player adds one mana of any color they choose.

Rampaging Ferocidon

Menace
Players can't gain life.
Whenever another creature enters the battlefield, Rampaging Ferocidon deals 1 damage to that creature's controller.

Crackle with Power

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

Magus of the Vineyard

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}.

Arcane Signet

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

Bubbling Muck

Until end of turn, whenever a player taps a Swamp for mana, that player adds an additional {B}.

Rootweaver Druid

When Rootweaver Druid enters the battlefield, 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.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Horizon Stone

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

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Genesis Hydra

When you cast this spell, reveal the top X cards of your library. You may put a nonland permanent card with mana value X or less from among them onto the battlefield. Then shuffle the rest into your library.
Genesis Hydra enters the battlefield with X +1/+1 counters on it.

Collective Voyage

Join forces — Starting with you, each player may pay any amount of mana. Each player searches their library for up to X basic land cards, where X is the total amount of mana paid this way, puts them onto the battlefield tapped, then shuffles.

Manabarbs

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

Rug of Smothering

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

Howling Mine

At the beginning of each player's draw step, if Howling Mine is untapped, that player draws an additional card.

Sol Ring

Mana Flare

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.

Command Tower

Kessig Wolf Run

{T}: Add {C}.
{X}{R}{G}, {T}: Target creature gets +X/+0 and gains trample until end of turn.

Swamp

Savageborn Hydra

Double strike
Savageborn Hydra enters the battlefield with X +1/+1 counters on it.
{1}{R/G}: Put a +1/+1 counter on Savageborn Hydra. Activate only as a sorcery.

Kazandu Nectarpot

Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Geode Rager

First strike
Landfall — Whenever a land enters the battlefield under your control, goad each creature target player controls. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

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 precombat 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.

Cut of the Profits

Casualty 3 (As you cast this spell, you may sacrifice a creature with power 3 or greater. When you do, copy this spell.)
You draw X cards and you lose X life.

Return to Nature

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

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.

Tangleroot

Whenever a player casts a creature spell, that player adds {G}.

Woodland Cemetery

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Fall of the Titans

Surge {X}{R} (You may cast this spell for its surge cost if you or a teammate has cast another spell this turn.)
Fall of the Titans deals X damage to each of up to two targets.

Scytheclaw Raptor

Whenever a player casts a spell, if it's not their turn, Scytheclaw Raptor deals 4 damage to them.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters the battlefield with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

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.

Blinkmoth Urn

At the beginning of each player's precombat main phase, if Blinkmoth Urn is untapped, that player adds {C} for each artifact they control.

Orc Army

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.

Barad-dûr

Barad-dûr enters the battlefield tapped unless you control a legendary creature.
{T}: Add {B}.
{X}{X}{B}, {T}: Amass Orcs X. Activate only if a creature died this turn.

Victory Chimes

Untap Victory Chimes during each other player's untap step.
{T}: A player of your choice adds {C}.

Neverwinter Hydra

As Neverwinter Hydra enters the battlefield, roll X d6. It enters with a number of +1/+1 counters on it equal to the total of those results.
Trample
Ward {4} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)

Exotic Orchard

Fangorn, Tree Shepherd

Treefolk you control have vigilance.
Whenever one or more Treefolk you control attack, add twice that much {G}.
You don't lose unspent green mana as steps and phases end.

Grazing Gladehart

Landfall — Whenever a land enters the battlefield under your control, you may gain 2 life.

Dictate of Karametra

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

New Frontiers

Each player may search their library for up to X basic land cards and put them onto the battlefield tapped. Then each player who searched their library this way shuffles.

Clan Defiance

Choose one or more —
• Clan Defiance deals X damage to target creature with flying.
• Clan Defiance deals X damage to target creature without flying.
• Clan Defiance deals X damage to target player or planeswalker.

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.

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Erebos's Intervention

Choose one —
• Target creature gets -X/-X until end of turn. You gain X life.
• Exile up to twice X target cards from graveyards.

Animist's Awakening

Reveal the top X cards of your library. Put all land cards from among them onto the battlefield tapped and the rest on the bottom of your library in a random order.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, untap those lands.

Aberrant

Ravenous (This creature enters the battlefield with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.)
Trample
Heavy Power Hammer — Whenever Aberrant deals combat damage to a player, destroy target artifact or enchantment that player controls.

Riveteers Overlook

When Riveteers Overlook enters the battlefield, sacrifice it. When you do, search your library for a basic Swamp, Mountain, or Forest card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Jaddi Offshoot

Defender
Landfall — Whenever a land enters the battlefield under your control, you gain 1 life.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Hungering Hydra

Hungering Hydra enters the battlefield with X +1/+1 counters on it.
Hungering Hydra can't be blocked by more than one creature.
Whenever Hungering Hydra is dealt damage, put that many +1/+1 counters on it. (It must survive the damage to get the counters.)

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.

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.