Boros Elite

Battalion — Whenever this creature and at least two other creatures attack, this creature gets +2/+2 until end of turn.

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.

Angelfire Ignition

Put two +1/+1 counters on target creature. It gains vigilance, trample, lifelink, indestructible, and haste until end of turn.
Flashback {2}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Gang Up

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Destroy target creature with power X or less.

Play of the Game

Assist (Another player can pay up to {6} of this spell's cost.)
Exile all nonland permanents.

Paladin Elizabeth Taggerdy

Battalion — Whenever Paladin Elizabeth Taggerdy and at least two other creatures attack, draw a card, then you may put a creature card with mana value X or less from your hand onto the battlefield tapped and attacking, where X is Paladin Elizabeth Taggerdy's power.

The Crowd Goes Wild

Assist (Another player can pay up to {X} of this spell's cost. You choose the value of X.)
Support X. (Put a +1/+1 counter on each of up to X target creatures.)
Each creature with a +1/+1 counter on it gains trample until end of turn.

Wojek Halberdiers

Battalion — Whenever this creature and at least two other creatures attack, this creature gains first strike until end of turn.

Daring Skyjek

Battalion — Whenever this creature and at least two other creatures attack, this creature gains flying until end of turn.

Huddle Up

Assist (Another player can pay up to {2} of this spell's cost.)
Two target players each draw a card.

Sontaran General

Trample, haste
Battalion — Whenever this creature and at least two other creatures attack, for each opponent, goad up to one target creature that player controls. Those creatures can't block this turn. (Until your next turn, they attack each combat if able and attack a player other than you if able.)

Firefist Striker

Battalion — Whenever this creature and at least two other creatures attack, target creature can't block this turn.