Sidar Jabari of Zhalfir

Eminence — Whenever you attack with one or more Knights, if Sidar Jabari of Zhalfir 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.

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.

Command Tower

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

Haytham Kenway

Protection from Assassins
Other Knights you control get +2/+2 and have protection from Assassins.
When Haytham Kenway enters, for each opponent, exile up to one target creature that player controls until Haytham Kenway leaves the battlefield.

Caduceus, Staff of Hermes

Equipped creature has lifelink.
As long as you have 30 or more life, equipped creature gets +5/+5 and has indestructible and "Prevent all damage that would be dealt to this creature."
Equip {W}{W}

Excalibur, Sword of Eden

This spell costs {X} less to cast, where X is the total mana value of historic permanents you control. (Artifacts, legendaries, and Sagas are historic.)
Equipped creature gets +10/+0 and has vigilance.
Equip legendary creature {2}

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.

Plains

Mjölnir, Storm Hammer

When Mjölnir enters, attach it to target legendary creature you control.
Whenever equipped creature attacks, tap target creature defending player controls and put a stun counter on it. Then Mjölnir deals damage to each opponent equal to the number of tapped creatures that opponent controls.
Equip {4}

Generous Gift

Destroy target permanent. Its controller creates a 3/3 green Elephant creature token.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Herald of Hoofbeats

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

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

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.)

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

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.

Swords to Plowshares

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

Counterspell

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Despark

Exile target permanent with mana value 4 or greater.

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Loyal Inventor

Vigilance
When Loyal Inventor enters, you may search your library for an artifact card, reveal it, then shuffle. Put that card into your hand if you control an Assassin. Otherwise, put that card on top of your library.

Raffine's Tower

({T}: Add {W}, {U}, or {B}.)
Raffine's Tower enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

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.)

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Swamp

Shay Cormac

{1}: Permanents your opponents control lose hexproof, indestructible, protection, shroud, and ward until end of turn.
Whenever a creature an opponent controls becomes the target of a spell or ability you control, put a bounty counter on that creature.
Whenever a creature with a bounty counter on it dies, put two +1/+1 counters on Shay Cormac.

Obscura Storefront

When Obscura Storefront enters, sacrifice it. When you do, search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to its mana value.

Island

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Three Tree City

As Three Tree City enters, choose a creature type.
{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to the number of creatures you control of the chosen type.

Akroma's Memorial

Creatures you control have flying, first strike, vigilance, trample, haste, and protection from black and from red.

Sol Ring

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Arcane Signet

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

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.

Vodalian Wave-Knight

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