Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)

Maybe too good

Kutzil, Malamet Exemplar

Your opponents can't cast spells during your turn.
Whenever one or more creatures you control each with power greater than its base power deals combat damage to a player, draw a card.

Citywide Bust

Destroy all creatures with toughness 4 or greater.

Emmara, Soul of the Accord

Whenever Emmara, Soul of the Accord becomes tapped, create a 1/1 white Soldier creature token with lifelink.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Added

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Beastmaster Ascension

Whenever a creature you control attacks, you may put a quest counter on Beastmaster Ascension.
As long as Beastmaster Ascension has seven or more quest counters on it, creatures you control get +5/+5.

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

Karametra's Favor

Enchant creature
When Karametra's Favor enters, draw a card.
Enchanted creature has "{T}: Add one mana of any color."

Queen Allenal of Ruadach

Queen Allenal of Ruadach's power and toughness are each equal to the number of creatures you control.
If one or more creature tokens would be created under your control, those tokens plus a 1/1 white Soldier creature token are created instead.

Camaraderie

You gain X life and draw X cards, where X is the number of creatures you control. Creatures you control get +1/+1 until end of turn.

Harvest Season

Search your library for up to X basic land cards, where X is the number of tapped creatures you control, put those cards onto the battlefield tapped, then shuffle.

Graypelt Refuge

Graypelt Refuge enters tapped.
When Graypelt Refuge enters, you gain 1 life.
{T}: Add {G} or {W}.

Devouring Light

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Exile target attacking or blocking creature.

Commander's Sphere

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

Elven Chorus

You may look at the top card of your library any time.
You may cast creature spells from the top of your library.
Creatures you control have "{T}: Add one mana of any color."

Overwhelming Instinct

Whenever you attack with three or more creatures, draw a card.

Elfhame Palace

Elfhame Palace enters tapped.
{T}: Add {G} or {W}.

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.)

Divine Visitation

If one or more creature tokens would be created under your control, that many 4/4 white Angel creature tokens with flying and vigilance are created instead.

Verdant Force

At the beginning of each upkeep, create a 1/1 green Saproling creature token.

Selesnya Guildmage

{3}{G}: Create a 1/1 green Saproling creature token.
{3}{W}: Creatures you control get +1/+1 until end of turn.

Slate of Ancestry

{4}, {T}, Discard your hand: Draw a card for each creature you control.

Eternal Witness

When Eternal Witness enters, you may return target card from your graveyard to your hand.

Jaspera Sentinel

Reach
{T}, Tap an untapped creature you control: Add one mana of any color.

Cadira, Caller of the Small

Trample
Whenever Cadira, Caller of the Small deals combat damage to a player, for each token you control, create a 1/1 white Rabbit creature token.

Felidar Retreat

Landfall — Whenever a land you control enters, choose one —
• Create a 2/2 white Cat Beast creature token.
• Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.

Vitu-Ghazi, the City-Tree

{T}: Add {C}.
{2}{G}{W}, {T}: Create a 1/1 green Saproling creature token.

Sol Ring

Talisman of Unity

{T}: Add {C}.
{T}: Add {G} or {W}. Talisman of Unity deals 1 damage to you.

Champion of Lambholt

Creatures with power less than Champion of Lambholt's power can't block creatures you control.
Whenever another creature you control enters, put a +1/+1 counter on Champion of Lambholt.

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Temple of Plenty

Temple of Plenty enters tapped.
When Temple of Plenty enters, scry 1.
{T}: Add {G} or {W}.

Thunderfoot Baloth

Trample
Lieutenant — As long as you control your commander, Thunderfoot Baloth gets +2/+2 and other creatures you control get +2/+2 and have trample.

White Sun's Zenith

Create X 2/2 white Cat creature tokens. Shuffle White Sun's Zenith into its owner's library.

Intangible Virtue

Creature tokens you control get +1/+1 and have vigilance.

Growing Ranks

At the beginning of your upkeep, populate. (Create a token that's a copy of a creature token you control.)

Nissa's Expedition

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Farhaven Elf

When Farhaven Elf enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Leafkin Druid

{T}: Add {G}. If you control four or more creatures, add {G}{G} instead.

Pledge of Unity

Put a +1/+1 counter on each creature you control. You gain 1 life for each creature you control.

Holdout Settlement

{T}: Add {C}. ({C} represents colorless mana.)
{T}, Tap an untapped creature you control: Add one mana of any color.

Collective Blessing

Dauntless Escort

Sacrifice Dauntless Escort: Creatures you control gain indestructible until end of turn.

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Overrun

Creatures you control get +3/+3 and gain trample until end of turn.

Blossoming Sands

Blossoming Sands enters tapped.
When Blossoming Sands enters, you gain 1 life.
{T}: Add {G} or {W}.

Juniper Order Ranger

Whenever another creature you control enters, put a +1/+1 counter on that creature and a +1/+1 counter on Juniper Order Ranger.

Maja, Bretagard Protector

Other creatures you control get +1/+1.
Landfall — Whenever a land you control enters, create a 1/1 white Human Warrior creature token.

Charismatic Conqueror

Vigilance
Whenever an artifact or creature an opponent controls enters untapped, they may tap that permanent. If they don't, you create a 1/1 white Vampire creature token with lifelink.

Presence of Gond

Enchant creature
Enchanted creature has "{T}: Create a 1/1 green Elf Warrior creature token."

Sundering Growth

Destroy target artifact or enchantment, then populate. (Create a token that's a copy of a creature token you control.)

Trostani Discordant

Other creatures you control get +1/+1.
When Trostani Discordant enters, create two 1/1 white Soldier creature tokens with lifelink.
At the beginning of your end step, each player gains control of all creatures they own.

Sporemound

Landfall — Whenever a land you control enters, create a 1/1 green Saproling creature token.

Nullmage Shepherd

Tap four untapped creatures you control: Destroy target artifact or enchantment.

Commander's Insignia

Creatures you control get +1/+1 for each time you've cast your commander from the command zone this game.

Rhys the Redeemed

{2}{G/W}, {T}: Create a 1/1 green and white Elf Warrior creature token.
{4}{G/W}{G/W}, {T}: For each creature token you control, create a token that's a copy of that creature.

Citanul Hierophants

Creatures you control have "{T}: Add {G}."

Tranquil Expanse

Tranquil Expanse enters tapped.
{T}: Add {G} or {W}.

Canopy Vista

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

March of the Multitudes

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Create X 1/1 white Soldier creature tokens with lifelink.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Idol of Oblivion

{T}: Draw a card. Activate only if you created a token this turn.
{8}, {T}, Sacrifice Idol of Oblivion: Create a 10/10 colorless Eldrazi creature token.

Loyal Guardian

Trample
Lieutenant — At the beginning of combat on your turn, if you control your commander, put a +1/+1 counter on each creature you control.

Dictate of Heliod

Forest

Great Oak Guardian

Flash (You may cast this spell any time you could cast an instant.)
Reach
When Great Oak Guardian enters, creatures target player controls get +2/+2 until end of turn. Untap them.

Plains

Command Tower

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

Skullclamp

Equipped creature gets +1/-1.
Whenever equipped creature dies, draw two cards.
Equip {1}

Hare Raising

Target creature you control gains vigilance and gets +X/+X until end of turn, where X is the number of creatures you control.

Pollen-Shield Hare

Pollen-Shield Hare // Hare Raising

Victory's Envoy

At the beginning of your upkeep, put a +1/+1 counter on each other creature you control.

Avacyn's Pilgrim

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Selesnya Evangel

{1}, {T}, Tap an untapped creature you control: Create a 1/1 green Saproling creature token.

Fortified Village

As Fortified Village enters, you may reveal a Forest or Plains card from your hand. If you don't, Fortified Village enters tapped.
{T}: Add {G} or {W}.

Hour of Reckoning

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Destroy all nontoken creatures.

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.

Conclave Tribunal

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
When Conclave Tribunal enters, exile target nonland permanent an opponent controls until Conclave Tribunal leaves the battlefield.

Arcane Signet

King Darien XLVIII

Other creatures you control get +1/+1.
{3}{G}{W}: Put a +1/+1 counter on King Darien and create a 1/1 white Soldier creature token.
Sacrifice King Darien: Creature tokens you control gain hexproof and indestructible until end of turn.

Scatter the Seeds

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Create three 1/1 green Saproling creature tokens.

Hornet Queen

Flying, deathtouch
When Hornet Queen enters, create four 1/1 green Insect creature tokens with flying and deathtouch.

Valor in Akros

Whenever a creature you control enters, creatures you control get +1/+1 until end of turn.