Mace of the Valiant

Equipped creature gets +1/+1 for each charge counter on Mace of the Valiant and has vigilance. (Attacking doesn't cause it to tap.)
Whenever a creature you control enters, put a charge counter on Mace of the Valiant.
Equip {3}

Boulder Rush

Target creature gets +2/+0 until end of turn. (Then exile this card. You may cast the creature later from exile.)

Rimrock Knight

Rimrock Knight // Boulder Rush

Belle of the Brawl

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Belle of the Brawl attacks, other Knights you control get +1/+0 until end of turn.

Cavalier of Dawn

Vigilance
When Cavalier of Dawn enters, destroy up to one target nonland permanent. Its controller creates a 3/3 colorless Golem artifact creature token.
When Cavalier of Dawn dies, return target artifact or enchantment card from your graveyard to your hand.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Blacklance Paragon

Flash
When Blacklance Paragon enters, target Knight gains deathtouch and lifelink until end of turn.

Profane Insight

You draw a card and you lose 1 life. (Then exile this card. You may cast the creature later from exile.)

Foulmire Knight

Foulmire Knight // Profane Insight

Plains

Burning-Yard Trainer

Trample, haste
When Burning-Yard Trainer enters, another target Knight you control gets +2/+2 and gains trample and haste until end of turn.

Midnight Reaper

Whenever a nontoken creature you control dies, this creature deals 1 damage to you and you draw a card.

Savai Crystal

{T}: Add {R}, {W}, or {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

Syr Konrad, the Grim

Whenever another creature dies, or a creature card is put into a graveyard from anywhere other than the battlefield, or a creature card leaves your graveyard, Syr Konrad, the Grim deals 1 damage to each opponent.
{1}{B}: Each player mills a card. (They each put the top card of their library into their graveyard.)

Rakdos Signet

Steelclaw Lance

Equipped creature gets +2/+2.
Equip Knight {1}
Equip {3}

Battle Display

Destroy target artifact. (Then exile this card. You may cast the creature later from exile.)

Embereth Shieldbreaker

Embereth Shieldbreaker // Battle Display

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

Sol Ring

Nomad Outpost

Nomad Outpost enters tapped.
{T}: Add {R}, {W}, or {B}.

Tournament Grounds

{T}: Add {C}.
{T}: Add {R}, {W}, or {B}. Spend this mana only to cast a Knight or Equipment spell.

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.

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.

Orzhov Signet

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

Knights' Charge

Whenever a Knight you control attacks, each opponent loses 1 life and you gain 1 life.
{6}{W}{B}, Sacrifice Knights' Charge: Return all Knight creature cards from your graveyard to the battlefield.

Castle Embereth

Castle Embereth enters tapped unless you control a Mountain.
{T}: Add {R}.
{1}{R}{R}, {T}: Creatures you control get +1/+0 until end of turn.

Castle Ardenvale

Castle Ardenvale enters tapped unless you control a Plains.
{T}: Add {W}.
{2}{W}{W}, {T}: Create a 1/1 white Human creature token.

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.

Silverwing Squadron

Flying, vigilance
Silverwing Squadron's power and toughness are each equal to the number of creatures you control.
Whenever Silverwing Squadron attacks, create a number of 2/2 white Knight creature tokens with vigilance equal to the number of opponents you have.

Shining Armor

Flash
When Shining Armor enters, attach it to target Knight you control.
Equipped creature gets +0/+2 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Boros Signet

Sunforger

Equipped creature gets +4/+0.
{R}{W}, Unattach Sunforger: Search your library for a red or white instant card with mana value 4 or less and cast that card without paying its mana cost. Then shuffle.
Equip {3}

Wintermoor Commander

Deathtouch
Wintermoor Commander's toughness is equal to the number of Knights you control.
Whenever Wintermoor Commander attacks, another target Knight you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Knight of the Ebon Legion

{2}{B}: Knight of the Ebon Legion gets +3/+3 and gains deathtouch until end of turn.
At the beginning of your end step, if a player lost 4 or more life this turn, put a +1/+1 counter on Knight of the Ebon Legion. (Damage causes loss of life.)

Embereth Skyblazer

During your turn, Embereth Skyblazer has flying.
Whenever Embereth Skyblazer attacks, you may pay {2}{R}. If you do, creatures you control get +X/+0 until end of turn, where X is the number of opponents you have.

Colossus Hammer

Equipped creature gets +10/+10 and loses flying.
Equip {8} ({8}: Attach to target creature you control. Equip only as a sorcery.)

Inspiring Veteran

Armored Skyhunter

Flying
Whenever Armored Skyhunter attacks, look at the top six cards of your library. You may put an Aura or Equipment card from among them onto the battlefield. If an Equipment is put onto the battlefield this way, you may attach it to a creature you control. Put the rest of those cards on the bottom of your library in a random order.

Despark

Exile target permanent with mana value 4 or greater.

Elite Headhunter

Menace (This creature can't be blocked except by two or more creatures.)
{B/R}{B/R}{B/R}, Sacrifice another creature or an artifact: Elite Headhunter deals 2 damage to target creature or planeswalker.

The Circle of Loyalty

This spell costs {1} less to cast for each Knight you control.
Creatures you control get +1/+1.
Whenever you cast a legendary spell, create a 2/2 white Knight creature token with vigilance.
{3}{W}, {T}: Create a 2/2 white Knight creature token with vigilance.

Alter Fate

Return target creature card from your graveyard to your hand. (Then exile this card. You may cast the creature later from exile.)

Order of Midnight

Order of Midnight // Alter Fate

Swamp

Worthy Knight

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

Mountain

Josu Vess, Lich Knight

Kicker {5}{B} (You may pay an additional {5}{B} as you cast this spell.)
Menace
When Josu Vess, Lich Knight enters, if it was kicked, create eight 2/2 black Zombie Knight creature tokens with menace.

Corpse Knight

Whenever another creature you control enters, each opponent loses 1 life.

Mortify

Command Tower

Swift End

Destroy target creature or planeswalker. You lose 2 life. (Then exile this card. You may cast the creature later from exile.)

Murderous Rider

Lifelink
When Murderous Rider dies, put it on the bottom of its owner's library.

Murderous Rider // Swift End

Crackling Doom

Crackling Doom deals 2 damage to each opponent. Each opponent sacrifices a creature with the greatest power among creatures that player controls.

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}

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

Open the Armory

Search your library for an Aura or Equipment card, reveal it, put it into your hand, then shuffle.

Embercleave

Flash
This spell costs {1} less to cast for each attacking creature you control.
When Embercleave enters, attach it to target creature you control.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3}

Rider in Need

Create a 2/2 white Knight creature token with vigilance. (Then exile this card. You may cast the creature later from exile.)

Lonesome Unicorn

Lonesome Unicorn // Rider in Need

Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

History of Benalia

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Create a 2/2 white Knight creature token with vigilance.
III — Knights you control get +2/+1 until end of turn.

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.

Fervent Champion

First strike, haste
Whenever Fervent Champion attacks, another target attacking Knight you control gets +1/+0 until end of turn.
Equip abilities you activate that target Fervent Champion cost {3} less to activate.

Castle Locthwain

Castle Locthwain enters tapped unless you control a Swamp.
{T}: Add {B}.
{1}{B}{B}, {T}: Draw a card, then you lose life equal to the number of cards in your hand.

Syr Gwyn, Hero of Ashvale

Vigilance, menace
Whenever an equipped creature you control attacks, you draw a card and you lose 1 life.
Equipment you control have equip Knight {0}.