Aeronaut Cavalry

Flying
When Aeronaut Cavalry enters, put a +1/+1 counter on another target Soldier you control.

Field Marshal

Other Soldier creatures get +1/+1 and have first strike. (They deal combat damage before creatures without first strike.)

Commander Mustard

Vigilance
Other Soldiers you control have vigilance, trample, and haste.
{2}{R}{W}: Until end of turn, Soldiers you control gain "Whenever this creature attacks, it deals 1 damage to defending player."

Auriok Steelshaper

Equip costs you pay cost {1} less.
As long as Auriok Steelshaper is equipped, each creature you control that's a Soldier or a Knight gets +1/+1.

Captain of the Watch

Vigilance (Attacking doesn't cause this creature to tap.)
Other Soldier creatures you control get +1/+1 and have vigilance.
When Captain of the Watch enters, create three 1/1 white Soldier creature tokens.

Hardened Escort

Whenever Hardened Escort attacks, another target creature you control gets +1/+0 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Valiant Veteran

Other Soldiers you control get +1/+1.
{3}{W}{W}, Exile Valiant Veteran from your graveyard: Put a +1/+1 counter on each Soldier you control.