Nethroi, Apex of Death

Mutate {4}{G/W}{B}{B} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Deathtouch, lifelink
Whenever this creature mutates, return any number of target creature cards with total power 10 or less from your graveyard to the battlefield.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Explosive Vegetation

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Krosan Verge

Krosan Verge enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Krosan Verge: Search your library for a Forest card and a Plains card, put them onto the battlefield tapped, then shuffle.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

Naya Charm

Choose one —
• Naya Charm deals 3 damage to target creature.
• Return target card from a graveyard to its owner's hand.
• Tap all creatures target player controls.

Growth Spiral

Draw a card. You may put a land card from your hand onto the battlefield.

Faeburrow Elder

Vigilance
Faeburrow Elder gets +1/+1 for each color among permanents you control.
{T}: For each color among permanents you control, add one mana of that color.

Forest

Echoing Truth

Return target nonland permanent and all other permanents with the same name as that permanent to their owners' hands.

Flood Plain

Flood Plain enters tapped.
{T}, Sacrifice Flood Plain: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

Knight of New Alara

Each other multicolored creature you control gets +1/+1 for each of its colors.

Unite the Coalition

Choose five. You may choose the same mode more than once.
• Target permanent phases out.
• Target player draws a card.
• Exile target player's graveyard.
• Unite the Coalition deals 2 damage to any target.
• Destroy target artifact or enchantment.

Transguild Courier

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Fusion Elemental

Jenson Carthalion, Druid Exile

Whenever you cast a multicolored spell, scry 1. If that spell was all colors, create a 4/4 white Angel creature token with flying and vigilance.
{5}, {T}: Add {W}{U}{B}{R}{G}.

Kodama's Reach

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.

Radiant Flames

Converge — Radiant Flames deals X damage to each creature, where X is the number of colors of mana spent to cast this spell.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters, draw a card.

Primeval Spawn

If Primeval Spawn would enter and it wasn't cast or no mana was spent to cast it, exile it instead.
Vigilance, trample, lifelink
When Primeval Spawn leaves the battlefield, exile the top ten cards of your library. You may cast any number of spells with total mana value 10 or less from among them without paying their mana costs.

Plains

Sultai Charm

Choose one —
• Destroy target monocolored creature.
• Destroy target artifact or enchantment.
• Draw two cards, then discard a card.

Exotic Orchard

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

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Cinder Glade

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

Abundant Growth

Enchant land
When Abundant Growth enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

O-Kagachi, Vengeful Kami

Flying, trample
Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

Grasslands

Grasslands enters tapped.
{T}, Sacrifice Grasslands: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

Atla Palani, Nest Tender

{2}, {T}: Create a 0/1 green Egg creature token with defender.
Whenever an Egg you control dies, reveal cards from the top of your library until you reveal a creature card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Prophetic Prism

When Prophetic Prism enters, draw a card.
{1}, {T}: Add one mana of any color.

Frontier Bivouac

Frontier Bivouac enters tapped.
{T}: Add {G}, {U}, or {R}.

Swamp

Glint-Eye Nephilim

Whenever Glint-Eye Nephilim deals combat damage to a player, draw that many cards.
{1}, Discard a card: Glint-Eye Nephilim gets +1/+1 until end of turn.

Fellwar Stone

Surrak Dragonclaw

Flash
This spell can't be countered.
Creature spells you control can't be countered.
Other creatures you control have trample.

Island

Coalition Relic

{T}: Add one mana of any color.
{T}: Put a charge counter on Coalition Relic.
At the beginning of your first main phase, remove all charge counters from Coalition Relic. Add one mana of any color for each charge counter removed this way.

Crystal Quarry

{T}: Add {C}.
{5}, {T}: Add {W}{U}{B}{R}{G}.

Rienne, Angel of Rebirth

Flying
Other multicolored creatures you control get +1/+0.
Whenever another multicolored creature you control dies, return it to its owner's hand at the beginning of the next end step.

Mana Cannons

Whenever you cast a multicolored spell, Mana Cannons deals X damage to any target, where X is the number of colors that spell is.

Search for Tomorrow

Search your library for a basic land card, put it onto the battlefield, then shuffle.
Suspend 2—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)

Merciless Eviction

Choose one —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all planeswalkers.

Obsidian Obelisk

Obsidian Obelisk enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a multicolored spell.

Rocky Tar Pit

Rocky Tar Pit enters tapped.
{T}, Sacrifice Rocky Tar Pit: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

Maelstrom Nexus

The first spell you cast each turn has cascade. (When you cast your first spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

Archelos, Lagoon Mystic

As long as Archelos, Lagoon Mystic is tapped, other permanents enter tapped.
As long as Archelos is untapped, other permanents enter untapped.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Iridian Maelstrom

Destroy each creature that isn't all colors.

Mountain Valley

Mountain Valley enters tapped.
{T}, Sacrifice Mountain Valley: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

Explore

You may play an additional land this turn.
Draw a card.

Path to the World Tree

When Path to the World Tree enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
{2}{W}{U}{B}{R}{G}, Sacrifice Path to the World Tree: You gain 2 life and draw two cards. Target opponent loses 2 life. Path to the World Tree deals 2 damage to up to one target creature. You create a 2/2 green Bear creature token.

Beast Within

Destroy target permanent. Its controller creates a 3/3 green Beast creature token.

Mystic Monastery

Mystic Monastery enters tapped.
{T}: Add {U}, {R}, or {W}.

Fallaji Wayfarer

Fallaji Wayfarer is all colors. This ability doesn't affect its color identity. (It can be in any deck whose commander's color identity includes green.)
Multicolored spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a multicolored spell pays for {1} or one mana of a color that creature is.)

Evolving Wilds

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

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Illuna, Apex of Wishes

Mutate {3}{R/G}{U}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flying, trample
Whenever this creature mutates, exile cards from the top of your library until you exile a nonland permanent card. Put that card onto the battlefield or into your hand.

Sylvan Reclamation

Exile up to two target artifacts and/or enchantments.
Basic landcycling {2} ({2}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Cultivate

Murmuring Bosk

({T}: Add {G}.)
As Murmuring Bosk enters, you may reveal a Treefolk card from your hand. If you don't, Murmuring Bosk enters tapped.
{T}: Add {W} or {B}. Murmuring Bosk deals 1 damage to you.

Chromanticore

Bestow {2}{W}{U}{B}{R}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying, first strike, vigilance, trample, lifelink
Enchanted creature gets +4/+4 and has flying, first strike, vigilance, trample, and lifelink.

Migration Path

Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.
Cycling {2} ({2}, Discard this card: Draw a card.)

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Terramorphic Expanse

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

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Lavalanche

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

Duneblast

Choose up to one creature. Destroy the rest.

Savage Lands

Savage Lands enters tapped.
{T}: Add {B}, {R}, or {G}.

Opulent Palace

Opulent Palace enters tapped.
{T}: Add {B}, {G}, or {U}.

Xyris, the Writhing Storm

Flying
Whenever an opponent draws a card except the first one they draw in each of their draw steps, create a 1/1 green Snake creature token.
Whenever Xyris, the Writhing Storm deals combat damage to a player, you and that player each draw that many cards.

Sandsteppe Citadel

Sandsteppe Citadel enters tapped.
{T}: Add {W}, {B}, or {G}.

Arcane Signet

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

Abzan Charm

Choose one —
• Exile target creature with power 3 or greater.
• You draw two cards and you lose 2 life.
• Distribute two +1/+1 counters among one or two target creatures.

Two-Headed Hellkite

Flying, menace, haste
Whenever Two-Headed Hellkite attacks, draw two cards.

Command Tower

Mountain

Bad River

Bad River enters tapped.
{T}, Sacrifice Bad River: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Canopy Vista

({T}: Add {G} or {W}.)
Canopy Vista enters tapped unless you control two or more basic lands.

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Tiller Engine

Whenever a land you control enters tapped, choose one —
• Untap that land.
• Tap target nonland permanent an opponent controls.

Time Wipe

Return a creature you control to its owner's hand, then destroy all creatures.

Coiling Oracle

When Coiling Oracle enters, reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, put that card into your hand.

Maelstrom Archangel

Flying
Whenever Maelstrom Archangel deals combat damage to a player, you may cast a spell from your hand without paying its mana cost.

Commander's Sphere

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

Terminate

Destroy target creature. It can't be regenerated.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Hero of Precinct One

Whenever you cast a multicolored spell, create a 1/1 white Human creature token.

Zaxara, the Exemplary

Deathtouch
{T}: Add two mana of any one color.
Whenever you cast a spell with {X} in its mana cost, create a 0/0 green Hydra creature token, then put X +1/+1 counters on it.

Selvala, Explorer Returned

Parley — {T}: Each player reveals the top card of their library. For each nonland card revealed this way, add {G} and you gain 1 life. Then each player draws a card.

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.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Jared Carthalion

+1: Create a 3/3 Kavu creature token with trample that's all colors.
−3: Choose up to two target creatures. For each of them, put a number of +1/+1 counters on it equal to the number of colors it is.
−6: Return target multicolored card from your graveyard to your hand. If that card was all colors, draw a card and create two Treasure tokens.
Jared Carthalion can be your commander.