Have

Kazandu Blademaster

First strike, vigilance
Whenever this creature or another Ally you control enters, you may put a +1/+1 counter on this creature.

Plains

Umara Raptor

Flying
Whenever this creature or another Ally you control enters, you may put a +1/+1 counter on this creature.

Glacial Fortress

This land enters tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Bala Ged Thief

Whenever this creature 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.

Hagra Diabolist

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

Ondu Cleric

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

Esper Panorama

{T}: Add {C}.
{1}, {T}, Sacrifice this land: Search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle.

Island

Day of Judgment

Mana Leak

Counter target spell unless its controller pays {3}.

Minion Reflector

Whenever a nontoken creature you control enters, you may pay {2}. If you do, create a token that's a copy of that creature, except it has haste and "At the beginning of the end step, sacrifice this permanent."

Mass Polymorph

Exile all creatures you control, then reveal cards from the top of your library until you reveal that many creature cards. Put all creature cards revealed this way onto the battlefield, then shuffle the rest of the revealed cards into your library.

Join the Ranks

Create two 1/1 white Soldier Ally creature tokens.

Hada Freeblade

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

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Swamp

Oblivion Ring

When this enchantment enters, exile another target nonland permanent.
When this enchantment leaves the battlefield, return the exiled card to the battlefield under its owner's control.

Rite of Replication

Kicker {5} (You may pay an additional {5} as you cast this spell.)
Create a token that's a copy of target creature. If this spell was kicked, create five of those tokens instead.

Ajani Goldmane

+1: You gain 2 life.
−1: Put a +1/+1 counter on each creature you control. Those creatures gain vigilance until end of turn.
−6: Create a white Avatar creature token. It has "This token's power and toughness are each equal to your life total."

Talus Paladin

Whenever this creature or another Ally you control enters, you may have Allies you control gain lifelink until end of turn, and you may put a +1/+1 counter on this creature.

Jwari Shapeshifter

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