Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Kazuul Warlord

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

Ondu Cleric

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

Semester's End

Exile any number of target creatures and/or planeswalkers you control. At the beginning of the next end step, return each of them to the battlefield under its owner's control. Each of them enters with an additional +1/+1 counter on it if it's a creature and an additional loyalty counter on it if it's a planeswalker.

Sea Gate Loremaster

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

Eerie Interlude

Exile any number of target creatures you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

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.

Three Tree Mascot

Changeling (This card is every creature type.)
{1}: Add one mana of any color. Activate only once each turn.

Ghostway

Exile each creature you control. Return those cards to the battlefield under their owner's control at the beginning of the next end step.

Jwari Shapeshifter

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

Tuktuk Scrapper

Whenever Tuktuk Scrapper or another Ally you control enters, 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.

Kabira Evangel

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

Harabaz Druid

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

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

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.

Resolute Blademaster

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

Heroic Intervention

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

Kalastria Healer

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

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.

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.

Lae'zel's Acrobatics

Exile all nontoken creatures you control, then roll a d20.
1—9 | Return those cards to the battlefield under their owner's control at the beginning of the next end step.
10—20 | Return those cards to the battlefield under their owner's control, then exile them again. Return those cards to the battlefield under their owner's control at the beginning of the next end step.