Malakir Soothsayer

Cohort — {T}, Tap an untapped Ally you control: You draw a card and you lose 1 life.

Hagra Diabolist

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

Forest

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's Chosen

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

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.

Hada Freeblade

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

Kalastria Healer

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

Swamp

Hero of Goma Fada

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

Evolving Wilds

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

Ondu Cleric

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

Plains

Bala Ged Thief

Whenever Bala Ged Thief or another Ally you control enters, 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.

Harabaz Druid

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

Beastcaller Savant

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

General Tazri

When General Tazri enters, 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.

Munda's Vanguard

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

Lantern Scout

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

Graypelt Hunter

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