Vodalian Wave-Knight

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

Marshal of Zhalfir

Other Knights you control get +1/+1.
{W}{U}, {T}: Tap another target creature.

Valiant Knight

Other Knights you control get +1/+1.
{3}{W}{W}: Knights you control gain double strike until end of turn.

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.

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

Swords to Plowshares

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

Corpse Knight

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

Werefox Bodyguard

Flash
When Werefox Bodyguard enters, exile up to one other target non-Fox creature until Werefox Bodyguard leaves the battlefield.
{1}{W}, Sacrifice Werefox Bodyguard: You gain 2 life.

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.

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

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.)

Locthwain Lancer

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

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.

Herald of Hoofbeats

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

Haakon, Stromgald Scourge

You may cast Haakon, Stromgald Scourge 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.

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.

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.

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.

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.

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.

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.)

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 artifact: Draw a card.")