Kor Entanglers

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

Three Visits

Search your library for a Forest card, put it onto the battlefield, then shuffle.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Lantern Scout

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

Sol Ring

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.

Rukarumel, Biologist

As Rukarumel, Biologist enters the battlefield, choose a creature type.
Slivers you control and nontoken creatures you control are the chosen type in addition to their other creature types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 1/1 colorless Sliver creature token.

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.

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.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

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.

Eternal Witness

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

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.

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.

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.

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.

Skyshroud Claim

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

Harabaz Druid

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

Arcane Signet

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

Ondu Champion

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

Murasa Pyromancer

Whenever Murasa Pyromancer or another Ally enters the battlefield under your control, you may have Murasa Pyromancer deal damage to target creature equal to the number of Allies you control.

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.

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.

Sakura-Tribe Elder

Sacrifice Sakura-Tribe Elder: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Cultivate

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.

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}.

Chasm Guide

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

Commander's Sphere

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

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.

Llanowar Elves

The Great Henge

This spell costs {X} less to cast, where X is the greatest power among creatures you control.
{T}: Add {G}{G}. You gain 2 life.
Whenever a nontoken creature enters the battlefield under your control, put a +1/+1 counter on it and draw a card.

Farseek

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

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.

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.)

Elvish Mystic

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.