Akroan Hoplite

Whenever this creature attacks, it gets +X/+0 until end of turn, where X is the number of attacking creatures you control.

Plains

Fairgrounds Warden

When this creature enters, exile target creature an opponent controls until this creature leaves the battlefield.

Elegant Parlor

({T}: Add {R} or {W}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Firemane Avenger

Flying
Battalion — Whenever this creature and at least two other creatures attack, this creature deals 3 damage to any target and you gain 3 life.

Sacred Foundry

({T}: Add {R} or {W}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Sunbillow Verge

{T}: Add {W}.
{T}: Add {R}. Activate only if you control a Mountain or a Plains.

Mountain

Archetype of Courage

Creatures you control have first strike.
Creatures your opponents control lose first strike and can't have or gain first strike.

Mentor of the Meek

Whenever another creature you control with power 2 or less enters, you may pay {1}. If you do, draw a card.

Healer's Hawk

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Assemble the Legion

At the beginning of your upkeep, put a muster counter on this enchantment. Then create a 1/1 red and white Soldier creature token with haste for each muster counter on this enchantment.

Aurelia, the Warleader

Flying, vigilance, haste
Whenever Aurelia attacks for the first time each turn, untap all creatures you control. After this phase, there is an additional combat phase.

Raise the Alarm

Create two 1/1 white Soldier creature tokens.

Tajic, Blade of the Legion

Indestructible
Battalion — Whenever Tajic and at least two other creatures attack, Tajic gets +5/+5 until end of turn.

Spear of Heliod

Creatures you control get +1/+1.
{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Frontline Medic

Battalion — Whenever this creature and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice this creature: Counter target spell with {X} in its mana cost unless its controller pays {3}.

Suture Priest

Whenever another creature you control enters, you may gain 1 life.
Whenever a creature an opponent controls enters, you may have that player lose 1 life.

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Shock

Odric, Master Tactician

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Odric and at least three other creatures attack, you choose which creatures block this combat and how those creatures block.