Hagra Diabolist

Whenever Hagra Diabolist or another Ally enters the battlefield under your control, you may have target player lose life equal to the number of Allies you control.

General Tazri

When General Tazri enters the battlefield, you may search your library for an Ally creature card, reveal it, put it into your hand, then shuffle.
{W}{U}{B}{R}{G}: Ally creatures you control get +X/+X until end of turn, where X is the number of colors among those creatures.

Resolute Blademaster

Rally — Whenever Resolute Blademaster or another Ally enters the battlefield under your control, creatures you control gain double strike until end of turn.

Forest

Hero of Goma Fada

Rally — Whenever Hero of Goma Fada or another Ally enters the battlefield under your control, creatures you control gain indestructible until end of turn.

Eladamri's Call

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

Enlightened Tutor

Search your library for an artifact or enchantment card, reveal it, then shuffle and put that card on top.

Noble Hierarch

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

Exotic Orchard

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

Bala Ged Thief

Whenever Bala Ged Thief or another Ally enters the battlefield under your control, target player reveals a number of cards from their hand equal to the number of Allies you control. You choose one of them. That player discards that card.

Zagoth Triome

({T}: Add {B}, {G}, or {U}.)
Zagoth Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Awakening Zone

At the beginning of your upkeep, you may create a 0/1 colorless Eldrazi Spawn creature token. It has "Sacrifice this creature: Add {C}."

Hada Freeblade

Whenever Hada Freeblade or another Ally enters the battlefield under your control, you may put a +1/+1 counter on Hada Freeblade.

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Swamp

Cascading Cataracts

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

Sol Ring

Drana, Liberator of Malakir

Flying, first strike
Whenever Drana, Liberator of Malakir deals combat damage to a player, put a +1/+1 counter on each attacking creature you control.

Beastcaller Savant

Haste
{T}: Add one mana of any color. Spend this mana only to cast a creature spell.

Bruse Tarl, Boorish Herder

Whenever Bruse Tarl, Boorish Herder enters the battlefield or attacks, target creature you control gains double strike and lifelink until end of turn.
Partner (You can have two commanders if both have partner.)

Bitterthorn, Nissa's Animus

Living weapon (When this Equipment enters the battlefield, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {3}

Mountain

Ondu Cleric

Whenever Ondu Cleric or another Ally enters the battlefield under your control, you may gain life equal to the number of Allies you control.

Weapons Trainer

Other creatures you control get +1/+0 as long as you control an Equipment.

Sterling Grove

Other enchantments you control have shroud. (They can't be the targets of spells or abilities.)
{1}, Sacrifice Sterling Grove: Search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Kalastria Healer

Rally — Whenever Kalastria Healer or another Ally enters the battlefield under your control, each opponent loses 1 life and you gain 1 life.

Command Tower

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

Graypelt Hunter

Trample
Whenever Graypelt Hunter or another Ally enters the battlefield under your control, you may put a +1/+1 counter on Graypelt Hunter.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Lingering Souls

Create two 1/1 white Spirit creature tokens with flying.
Flashback {1}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Highland Berserker

Whenever Highland Berserker or another Ally enters the battlefield under your control, you may have Ally creatures you control gain first strike until end of turn.

Firemantle Mage

Rally — Whenever Firemantle Mage or another Ally enters the battlefield under your control, creatures you control gain menace until end of turn. (A creature with menace can't be blocked except by two or more creatures.)

Joraga Bard

Whenever Joraga Bard or another Ally enters the battlefield under your control, you may have Ally creatures you control gain vigilance until end of turn.

Halimar Excavator

Whenever Halimar Excavator or another Ally enters the battlefield under your control, target player mills X cards, where X is the number of Allies you control.

Kazuul Warlord

Whenever Kazuul Warlord or another Ally enters the battlefield under your control, you may put a +1/+1 counter on each Ally creature you control.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or haste.)

Harabaz Druid

{T}: Add X mana of any one color, where X is the number of Allies you control.

Ondu Champion

Rally — Whenever Ondu Champion or another Ally enters the battlefield under your control, creatures you control gain trample until end of turn.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Akoum Flameseeker

Cohort — {T}, Tap an untapped Ally you control: Discard a card. If you do, draw a card.

Kenrith's Transformation

Enchant creature
When Kenrith's Transformation enters the battlefield, draw a card.
Enchanted creature loses all abilities and is a green Elk creature with base power and toughness 3/3. (It loses all other card types and creature types.)

Kor Entanglers

Rally — Whenever Kor Entanglers or another Ally enters the battlefield under your control, tap target creature an opponent controls.

Drana's Emissary

Flying
At the beginning of your upkeep, each opponent loses 1 life and you gain 1 life.

Plains

Expedition Envoy

Thran Dynamo

Bojuka Brigand

Bojuka Brigand can't block.
Whenever Bojuka Brigand or another Ally enters the battlefield under your control, you may put a +1/+1 counter on Bojuka Brigand.

Angelic Captain

Flying
Whenever Angelic Captain attacks, it gets +1/+1 until end of turn for each other attacking Ally.

Gyre Engineer

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters the battlefield, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Bayou

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Savai Triome

({T}: Add {R}, {W}, or {B}.)
Savai Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Talus Paladin

Whenever Talus Paladin or another Ally enters the battlefield under your control, you may have Allies you control gain lifelink until end of turn, and you may put a +1/+1 counter on Talus Paladin.

Agadeem Occultist

{T}: Put target creature card from an opponent's graveyard onto the battlefield under your control if its mana value is less than or equal to the number of Allies you control.

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
Indatha Triome enters the battlefield tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Makindi Patrol

Rally — Whenever Makindi Patrol or another Ally enters the battlefield under your control, creatures you control gain vigilance until end of turn.

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Kazandu Blademaster

First strike, vigilance
Whenever Kazandu Blademaster or another Ally enters the battlefield under your control, you may put a +1/+1 counter on Kazandu Blademaster.

Veteran Warleader

Veteran Warleader's power and toughness are each equal to the number of creatures you control.
Tap another untapped Ally you control: Veteran Warleader gains your choice of first strike, vigilance, or trample until end of turn.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Cliffside Lookout

{4}{W}: Creatures you control get +1/+1 until end of turn.

Sea Gate Loremaster

{T}: Draw a card for each Ally you control.

Brokers Ascendancy

At the beginning of your end step, put a +1/+1 counter on each creature you control and a loyalty counter on each planeswalker you control.

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Lantern Scout

Rally — Whenever Lantern Scout or another Ally enters the battlefield under your control, creatures you control gain lifelink until end of turn.

Boros Charm

Choose one —
• Boros Charm deals 4 damage to target player or planeswalker.
• Permanents you control gain indestructible until end of turn.
• Target creature gains double strike until end of turn.

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Jwari Shapeshifter

You may have Jwari Shapeshifter enter the battlefield as a copy of any Ally creature on the battlefield.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Spectral Procession

Create three 1/1 white Spirit creature tokens with flying.

Drana's Chosen

Cohort — {T}, Tap an untapped Ally you control: Create a tapped 2/2 black Zombie creature token.

Kabira Evangel

Whenever Kabira Evangel or another Ally enters the battlefield under your control, you may choose a color. If you do, Allies you control gain protection from the chosen color until end of turn.

Tuktuk Scrapper

Whenever Tuktuk Scrapper or another Ally enters the battlefield under your control, you may destroy target artifact. If that artifact is put into a graveyard this way, Tuktuk Scrapper deals damage to that artifact's controller equal to the number of Allies you control.

Chasm Guide

Rally — Whenever Chasm Guide or another Ally enters the battlefield under your control, creatures you control gain haste until end of turn.

Grovetender Druids

Rally — Whenever Grovetender Druids or another Ally enters the battlefield under your control, you may pay {1}. If you do, create a 1/1 green Plant creature token.

Angel of Renewal

Flying
When Angel of Renewal enters the battlefield, you gain 1 life for each creature you control.

Skyrider Elf

Flying
Converge — Skyrider Elf enters the battlefield with a +1/+1 counter on it for each color of mana spent to cast it.

Affa Protector

Akoum Battlesinger

Haste
Whenever Akoum Battlesinger or another Ally enters the battlefield under your control, you may have Ally creatures you control get +1/+0 until end of turn.

Munda's Vanguard

Cohort — {T}, Tap an untapped Ally you control: Put a +1/+1 counter on each creature you control.