Boros Elite

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

Gideon's Lawkeeper

Makeshift Battalion

Battalion — Whenever Makeshift Battalion and at least two other creatures attack, put a +1/+1 counter on Makeshift Battalion.

Thraben Inspector

When Thraben Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Pressure Point

Omen of the Sun

Flash
When Omen of the Sun enters, create two 1/1 white Human Soldier creature tokens and you gain 2 life.
{2}{W}, Sacrifice Omen of the Sun: Scry 2.

Ancestral Blade

When Ancestral Blade enters, create a 1/1 white Soldier creature token, then attach Ancestral Blade to it.
Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Plains

Veteran Armorsmith

Other Soldier creatures you control get +0/+1.

Ampryn Tactician

When Ampryn Tactician enters, creatures you control get +1/+1 until end of turn.

Guardians' Pledge

White creatures you control get +2/+2 until end of turn.

Idyllic Grange

({T}: Add {W}.)
Idyllic Grange enters tapped unless you control three or more other Plains.
When Idyllic Grange enters untapped, put a +1/+1 counter on target creature you control.

Guided Strike

Target creature gets +1/+0 and gains first strike until end of turn.
Draw a card.