Brute Strength

Target creature gets +3/+1 and gains trample until end of turn. (It can deal excess combat damage to the player or planeswalker it's attacking.)

Outnumber

Outnumber deals damage to target creature equal to the number of creatures you control.

Trusted Pegasus

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Trusted Pegasus attacks, target attacking creature without flying gains flying until end of turn.

Nahiri, the Harbinger

+2: You may discard a card. If you do, draw a card.
−2: Exile target enchantment, tapped artifact, or tapped creature.
−8: Search your library for an artifact or creature card, put it onto the battlefield, then shuffle. It gains haste. Return it to your hand at the beginning of the next end step.

Goblin Smuggler

Haste (This creature can attack and {T} as soon as it comes under your control.)
{T}: Another target creature with power 2 or less can't be blocked this turn.

Wind-Scarred Crag

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

Firemane Avenger

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

Frenzied Goblin

Whenever this creature attacks, you may pay {R}. If you do, target creature can't block this turn.

Heroic Reinforcements

Create two 1/1 white Soldier creature tokens. Until end of turn, creatures you control get +1/+1 and gain haste. (They can attack and {T} this turn.)

Plains

Filigree Familiar

When Filigree Familiar enters, you gain 2 life.
When Filigree Familiar dies, draw a card.

Sungrace Pegasus

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

Chitinous Cloak

Equipped creature gets +2/+2 and has menace. (It can't be blocked except by two or more creatures.)
Equip {3}

Mountain

Break Through the Line

{R}: Target creature with power 2 or less gains haste until end of turn and can't be blocked this turn.

Enchant creature
Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Thrilling Discovery

You gain 2 life. Then you may discard two cards. If you do, draw three cards.

Pyromancer's Assault

Whenever you cast your second spell each turn, Pyromancer's Assault deals 2 damage to any target.