Argivian Cavalier

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
When this creature enters, create a 1/1 white Soldier creature token.

Yavimaya Steelcrusher

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
{1}, Sacrifice this creature: Destroy target artifact.

Aven Squire

Flying
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Sighted-Caste Sorcerer

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{U}: This creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Goblin Champion

Haste
Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Argivian Phalanx

Affinity for creatures (This spell costs {1} less to cast for each creature you control.)
Vigilance (Attacking doesn't cause this creature to tap.)

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Plains

War Falcon

Flying
This creature can't attack unless you control a Knight or a Soldier.

Fencing Ace

Double strike (This creature deals both first-strike and regular combat damage.)

Mountain

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Akrasan Squire

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)

Martyr's Soul

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.)
When this creature enters, if you control no tapped lands, put two +1/+1 counters on it.