Venerable Knight

When Venerable Knight dies, put a +1/+1 counter on target Knight you control.

Knight of the White Orchid

First strike
When Knight of the White Orchid enters, if an opponent controls more lands than you, you may search your library for a Plains card, put it onto the battlefield, then shuffle.

Cavalry Drillmaster

When Cavalry Drillmaster enters, target creature gets +2/+0 and gains first strike until end of turn. (It deals combat damage before creatures without first strike.)

Windbrisk Heights

Hideaway 4 (When this land enters, look at the top four cards of your library, exile one face down, then put the rest on the bottom in a random order.)
Windbrisk Heights enters tapped.
{T}: Add {W}.
{W}, {T}: You may play the exiled card without paying its mana cost if you attacked with three or more creatures this turn.

Plains

Knight's Pledge

Enchant creature
Enchanted creature gets +2/+2.

Acclaimed Contender

When Acclaimed Contender enters, if you control another Knight, look at the top five cards of your library. You may reveal a Knight, Aura, Equipment, or legendary artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Garrison Griffin

Flying
Whenever Garrison Griffin attacks, target Knight you control gains flying until end of turn.

Dizzying Swoop

Tap up to two target creatures. (Then exile this card. You may cast the creature later from exile.)

Ardenvale Tactician

Ardenvale Tactician // Dizzying Swoop

Youthful Knight

War Falcon

Flying
War Falcon can't attack unless you control a Knight or a Soldier.

Unbreakable Formation

Creatures you control gain indestructible until end of turn.
Addendum — If you cast this spell during your main phase, put a +1/+1 counter on each of those creatures and they gain vigilance until end of turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Gird for Battle

Put a +1/+1 counter on each of up to two target creatures.

Daring Skyjek

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