Gatecrash

Assemble the Legion | Enchantment | | At the beginning of your upkeep, put a muster counter on Assemble the Legion. Then create a 1/1 red and white Soldier creature token with haste for each muster counter on Assemble the Legion. | Eric Deschamps

Firemane Avenger | Creature | Angel | 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. | Wayne Reynolds

Foundry Champion | Creature | Elemental Soldier | When Foundry Champion enters the battlefield, it deals damage to any target equal to the number of creatures you control. {R}: Foundry Champion gets +1/+0 until end of turn. {W}: Foundry Champion gets +0/+1 until end of turn. | Todd Lockwood

Spark Trooper | Creature | Elemental Soldier | Trample, lifelink, haste At the beginning of the end step, sacrifice Spark Trooper. | James Ryman

Boros Reckoner | Creature | Minotaur Wizard | Whenever Boros Reckoner is dealt damage, it deals that much damage to any target. {R/W}: Boros Reckoner gains first strike until end of turn. | Howard Lyon

Clan Defiance | Sorcery | | Choose one or more — • Clan Defiance deals X damage to target creature with flying. • Clan Defiance deals X damage to target creature without flying. • Clan Defiance deals X damage to target player or planeswalker. | Daarken

Gruul Ragebeast | Creature | Beast | Whenever Gruul Ragebeast or another creature enters the battlefield under your control, that creature fights target creature an opponent controls. | Dave Kendall

Rubblehulk | Creature | Elemental | Rubblehulk's power and toughness are each equal to the number of lands you control. Bloodrush — {1}{R}{G}, Discard Rubblehulk: Target attacking creature gets +X/+X until end of turn, where X is the number of lands you control. | Raymond Swanland

Signal the Clans | Instant | | Search your library for three creature cards and reveal them. If you reveal three cards with different names, choose one of them at random and put that card into your hand. Shuffle the rest into your library. | Dave Kendall

Rubblebelt Raiders | Creature | Human Warrior | Whenever Rubblebelt Raiders attacks, put a +1/+1 counter on it for each attacking creature you control. | Chippy