Knightly Valor

Enchant creature
When Knightly Valor enters, create a 2/2 white Knight creature token with vigilance. (Attacking doesn't cause it to tap.)
Enchanted creature gets +2/+2 and has vigilance.

Diamond Knight

Vigilance (Attacking doesn't cause this creature to tap.)
As Diamond Knight enters, choose a color.
Whenever you cast a spell of the chosen color, put a +1/+1 counter on Diamond Knight.

Paladin of Atonement

At the beginning of each upkeep, if you lost life last turn, put a +1/+1 counter on Paladin of Atonement.
When Paladin of Atonement dies, you gain life equal to its toughness.

Enchant creature
Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)

Call the Cavalry

Create two 2/2 white Knight creature tokens with vigilance.

Orzhov Locket

{T}: Add {W} or {B}.
{W/B}{W/B}{W/B}{W/B}, {T}, Sacrifice Orzhov Locket: Draw two cards.

Bring Back

Create two 1/1 white Human creature tokens. (Then exile this card. You may cast the creature later from exile.)

Oakhame Ranger

{T}: Creatures you control get +1/+1 until end of turn.

Oakhame Ranger // Bring Back

Benalish Marshal

Gallant Cavalry

Vigilance (Attacking doesn't cause this creature to tap.)
When Gallant Cavalry enters, create a 2/2 white Knight creature token with vigilance.

Sigiled Sword of Valeron

Equipped creature gets +2/+0, has vigilance, and is a Knight in addition to its other types.
Whenever equipped creature attacks, create a 2/2 white Knight creature token with vigilance that's attacking.
Equip {3}

Tresserhorn Skyknight

Flying
Prevent all damage that would be dealt to Tresserhorn Skyknight by creatures with first strike.

Syr Alin, the Lion's Claw

First strike
Whenever Syr Alin, the Lion's Claw attacks, other creatures you control get +1/+1 until end of turn.

Knight Watch

Parhelion Patrol

Flying, vigilance
Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

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

Swamp

Kaya, Bane of the Dead

Your opponents and permanents your opponents control with hexproof can be the targets of spells and abilities you control as though they didn't have hexproof.
−3: Exile target creature.

Knight of the Tusk

Vigilance (Attacking doesn't cause this creature to tap.)

Curry Favor

You gain X life and each opponent loses X life, where X is the number of Knights you control.

Smitten Swordmaster

Smitten Swordmaster // Curry Favor

Markov Dreadknight

Flying
{2}{B}, Discard a card: Put two +1/+1 counters on Markov Dreadknight.

Forsaken Sanctuary

Forsaken Sanctuary enters tapped.
{T}: Add {W} or {B}.

Gideon's Phalanx

Create four 2/2 white Knight creature tokens with vigilance.
Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, creatures you control gain indestructible until end of turn.

Knight of Dusk

{B}{B}: Destroy target creature blocking Knight of Dusk.

Knight of Malice

First strike
Hexproof from white (This creature can't be the target of white spells or abilities your opponents control.)
Knight of Malice gets +1/+0 as long as any player controls a white permanent.

Worthy Knight

Whenever you cast a Knight spell, create a 1/1 white Human creature token.

Manalith

Cabal Paladin

Whenever you cast a historic spell, Cabal Paladin deals 2 damage to each opponent. (Artifacts, legendaries, and Sagas are historic.)

Faithbearer Paladin

Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Jousting Lance

Equipped creature gets +2/+0.
During your turn, equipped creature has first strike.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Aryel, Knight of Windgrace

Vigilance
{2}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.
{B}, {T}, Tap X untapped Knights you control: Destroy target creature with power X or less.

Plains

Luminous Bonds

Enchant creature
Enchanted creature can't attack or block.

Inspiring Captain

When Inspiring Captain enters, creatures you control get +1/+1 until end of turn.

Knight's Pledge

Enchant creature
Enchanted creature gets +2/+2.

Concealed Courtyard

Concealed Courtyard enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.