Haakon, Stromgald Scourge

You may cast this card from your graveyard, but not from anywhere else.
As long as Haakon is on the battlefield, you may cast Knight spells from your graveyard.
When Haakon dies, you lose 2 life.

Exsanguinator Cavalry

Menace, lifelink
Whenever a Knight you control deals combat damage to a player, put a +1/+1 counter on that creature and create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this token: Draw a card.")

Sol Ring

Sorin, Grim Nemesis

+1: Reveal the top card of your library and put that card into your hand. Each opponent loses life equal to its mana value.
−X: Sorin deals X damage to target creature or planeswalker and you gain X life.
−9: Create a number of 1/1 black Vampire Knight creature tokens with lifelink equal to the highest life total among all players.

Knight

Locthwain Lancer

Menace
Whenever a nontoken Knight you control dies, each opponent loses 1 life and you draw a card.

Summon: Knights of Round

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after V.)
I, II, III, IV — Create three 2/2 white Knight creature tokens.
V — Ultimate End — Other creatures you control get +2/+2 until end of turn. Put an indestructible counter on each of them.
Indestructible

Ardenvale Fealty

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

Virtue of Loyalty

At the beginning of your end step, put a +1/+1 counter on each creature you control. Untap those creatures.

Virtue of Loyalty // Ardenvale Fealty

Bahamut, Warden of Light

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Wings of Light — Put a +1/+1 counter on each other creature you control. Those creatures gain flying until end of turn.
III — Gigaflare — Destroy target permanent. Exile Bahamut, then return it to the battlefield (front face up).
Flying

Dion, Bahamut's Dominant

Dragonfire Dive — During your turn, Dion and other Knights you control have flying.
When Dion enters, create a 2/2 white Knight creature token.
{4}{W}{W}, {T}: Exile Dion, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery.

Dion, Bahamut's Dominant // Bahamut, Warden of Light

Knight Exemplar

First strike (This creature deals combat damage before creatures without first strike.)
Other Knight creatures you control get +1/+1 and have indestructible. (Damage and effects that say "destroy" don't destroy them.)

Vodalian Wave-Knight

Whenever you draw a card, put a +1/+1 counter on each other Merfolk and/or Knight you control.

Worthy Knight

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

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Sidar Jabari of Zhalfir

Eminence — Whenever you attack with one or more Knights, if Sidar Jabari is in the command zone or on the battlefield, draw a card, then discard a card.
Flying, first strike
Whenever Sidar Jabari deals combat damage to a player, return target Knight creature card from your graveyard to the battlefield.

Counterspell

Diamond Knight

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

Syr Cadian, Knight Owl

Knightlifelink (Damage dealt by Knights you control also causes you to gain that much life.)
{W}: Syr Cadian gains vigilance until end of turn. Activate only from sunrise to sunset.
{B}: Syr Cadian gains flying until end of turn. Activate only from sunset to sunrise.

Kinsbaile Cavalier

Knight creatures you control have double strike.

Teferi Akosa of Zhalfir

+1: Draw two cards. Then discard two cards unless you discard a creature card.
−2: You get an emblem with "Knights you control get +1/+0 and have ward {1}."
−3: Tap any number of untapped creatures you control. When you do, shuffle target nonland permanent an opponent controls with mana value X or less into its owner's library, where X is the number of creatures tapped this way.

Invasion of New Phyrexia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, create X 2/2 white and blue Knight creature tokens with vigilance.

Invasion of New Phyrexia // Teferi Akosa of Zhalfir

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Swamp

Sun Quan, Lord of Wu

Creatures you control have horsemanship. (They can't be blocked except by creatures with horsemanship.)

Templar Knight

Vigilance
{W}, Tap five untapped attacking creatures you control named Templar Knight: Search your library for a legendary artifact card, put it onto the battlefield, then shuffle.
A deck can have any number of cards named Templar Knight.

Knights' Charge

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

Kinscaer Sentry

First strike, lifelink
Whenever this creature attacks, you may put a creature card with mana value X or less from your hand onto the battlefield tapped and attacking, where X is the number of attacking creatures you control.

Plains

Acclaimed Contender

When this creature 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.

Dimir Signet

Rosecot Knight

Vigilance
When this creature enters, look at the top six cards of your library. You may reveal an artifact or enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order. If you didn't put a card into your hand this way, put a +1/+1 counter on this creature.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Halo Fountain

{W}, {T}, Untap a tapped creature you control: Create a 1/1 green and white Citizen creature token.
{W}{W}, {T}, Untap two tapped creatures you control: Draw a card.
{W}{W}{W}{W}{W}, {T}, Untap fifteen tapped creatures you control: You win the game.

Herald of Hoofbeats

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Other Knights you control have horsemanship.

Chivalric Alliance

Whenever you attack with two or more creatures, draw a card.
{2}, Discard a card: Create a 2/2 white and blue Knight creature token with vigilance.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Thrumming Stone

Spells you cast have ripple 4. (Whenever you cast a spell, you may reveal the top four cards of your library. You may cast spells with the same name as that spell from among the revealed cards without paying their mana costs. Put the rest on the bottom of your library.)

Arcane Signet

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

Human

Doctor spells you cast cost {1} less to cast.

Azorius Signet

Island

Valiant Endeavor

Roll two d6 and choose one result. Destroy each creature with power greater than or equal to that result. Then create a number of 2/2 white Knight creature tokens with vigilance equal to the other result.

Swords to Plowshares

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

Knight of the White Orchid

First strike
When this creature 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.

Sautekh Immortal

Flash
Elite Troops — This creature enters with a +1/+1 counter on it for each creature that died this turn.

Orzhov Signet

The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

The Circle of Loyalty

Affinity for Knights (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.