Unbounded Potential

Choose one —
• Put a +1/+1 counter on each of up to two target creatures.
• Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)
Entwine {3}{W} (Choose both if you pay the entwine cost.)

Shoulder to Shoulder

Support 2. (Put a +1/+1 counter on each of up to two target creatures.)
Draw a card.

Hearts on Fire

One or two target creatures each get +2/+1 until end of turn.

Brigone, Soldier of Meletis

Vigilance
Heroic — Whenever you cast a spell that targets Brigone, put a +1/+1 counter on Brigone.
{T}, Remove a +1/+1 counter from Brigone: Draw a card.

Boros Guildgate

This land enters tapped.
{T}: Add {R} or {W}.

Vanguard of Brimaz

Vigilance
Heroic — Whenever you cast a spell that targets this creature, create a 1/1 white Cat Soldier creature token with vigilance.

Battlefield Forge

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

Rosnakht, Heir of Rohgahh

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
Heroic — Whenever you cast a spell that targets Rosnakht, create a 0/1 red Kobold creature token named Kobolds of Kher Keep.

Phalanx Leader

Heroic — Whenever you cast a spell that targets this creature, put a +1/+1 counter on each creature you control.

Coordinated Assault

Up to two target creatures each get +1/+0 and gain first strike until end of turn. (They deal combat damage before creatures without first strike.)

Slayers' Stronghold

{T}: Add {C}.
{R}{W}, {T}: Target creature gets +2/+0 and gains vigilance and haste until end of turn.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Heroes' Hangout

Choose one —
• Date Night — Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.
• Patrol Night — One or two target creatures each get +1/+0 and gain first strike until end of turn.

Getting

Opera Love Song

Choose one —
• Exile the top two cards of your library. You may play those cards until your next end step.
• One or two target creatures each get +2/+0 until end of turn.

Restless Bivouac

This land enters tapped.
{T}: Add {R} or {W}.
{1}{R}{W}: This land becomes a 2/2 red and white Ox creature until end of turn. It's still a land.
Whenever this land attacks, put a +1/+1 counter on target creature you control.

Cauldron Haze

Choose any number of target creatures. Each of those creatures gains persist until end of turn. (When it dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Burning Sun's Fury

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
Up to two target creatures each get +2/+0 and gain haste until end of turn.

Witch's Mark

You may discard a card. If you do, draw two cards.
Create a Wicked Role token attached to up to one target creature you control. (If you control another Role on it, put that one into the graveyard. Enchanted creature gets +1/+1. When this token is put into a graveyard, each opponent loses 1 life.)

Hero of the Nyxborn

When this creature enters, create a 1/1 white Human Soldier creature token.
Whenever you cast a spell that targets this creature, creatures you control get +1/+0 until end of turn.

Protection Magic

Put a shield counter on each of up to three target creatures. (If a creature with a shield counter would be dealt damage or destroyed, remove a shield counter from it instead.)

Tenth District Legionnaire

Haste
Whenever you cast a spell that targets this creature, put a +1/+1 counter on this creature, then scry 1.

Dragon's Rage Channeler

Whenever you cast a noncreature spell, surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
Delirium — As long as there are four or more card types among cards in your graveyard, this creature gets +2/+2, has flying, and attacks each combat if able.

Hero of the Games

Whenever you cast a spell that targets this creature, creatures you control get +1/+0 until end of turn.

Anax and Cymede

First strike, vigilance
Heroic — Whenever you cast a spell that targets Anax and Cymede, creatures you control get +1/+1 and gain trample until end of turn.

Plains

Mountain

Cleon, Merry Champion

Double strike
Heroic — Whenever you cast a spell that targets Cleon, exile the top card of your library. You may play that card until the end of your next turn.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Akroan Crusader

Heroic — Whenever you cast a spell that targets this creature, create a 1/1 red Soldier creature token with haste. (It can attack and {T} as soon as it comes under your control.)