Drogskol Reinforcements

Melee (Whenever this creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)
Other Spirits you control have melee.
Prevent all noncombat damage that would be dealt to Spirits you control.

Dauthi Mercenary

Shadow (This creature can block or be blocked by only creatures with shadow.)
{1}{B}: Dauthi Mercenary gets +1/+0 until end of turn.

Getting more of

Knight of Stromgald

Protection from white
{B}: Knight of Stromgald gains first strike until end of turn.
{B}{B}: Knight of Stromgald gets +1/+0 until end of turn.

Torsten Von Ursus

Soltari Crusader

Shadow (This creature can block or be blocked by only creatures with shadow.)
{1}{W}: Soltari Crusader gets +1/+0 until end of turn.

Paladin of the Bloodstained

When Paladin of the Bloodstained enters, create a 1/1 white Vampire creature token with lifelink.

Knight of Dawn

First strike
{W}{W}: Knight of Dawn gains protection from the color of your choice until end of turn.

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.

White Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from black (This creature can't be blocked, targeted, dealt damage, or enchanted by anything black.)

Castle

Untapped creatures you control get +0/+2.

Crusade

Zhalfirin Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{W}{W}: Zhalfirin Knight gains first strike until end of turn.

Aysen Crusader

Aysen Crusader's power and toughness are each equal to 2 plus the number of Soldiers and Warriors you control.

Shadow Rider

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)

Cadaverous Knight

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{1}{B}{B}: Regenerate Cadaverous Knight.

Moonshaker Cavalry

Flying
When Moonshaker Cavalry enters, creatures you control gain flying and get +X/+X until end of turn, where X is the number of creatures you control.

Knight of Dusk

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

Márton Stromgald

Whenever Márton Stromgald attacks, other attacking creatures get +1/+1 until end of turn for each attacking creature other than Márton Stromgald.
Whenever Márton Stromgald blocks, other blocking creatures get +1/+1 until end of turn for each blocking creature other than Márton Stromgald.

Soltari Lancer

Shadow (This creature can block or be blocked by only creatures with shadow.)
Soltari Lancer has first strike as long as it's attacking.

Order of the White Shield

Protection from black
{W}: Order of the White Shield gains first strike until end of turn.
{W}{W}: Order of the White Shield gets +1/+0 until end of turn.

Black Knight

First strike (This creature deals combat damage before creatures without first strike.)
Protection from white (This creature can't be blocked, targeted, dealt damage, or enchanted by anything white.)

Knighthood

Knight of Valor

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
{1}{W}: Each creature without flanking blocking Knight of Valor gets -1/-1 until end of turn. Activate only once each turn.

Varchild's War-Riders

Cumulative upkeep—Have an opponent create a 1/1 red Survivor creature token. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Trample; rampage 1 (Whenever this creature becomes blocked, it gets +1/+1 until end of turn for each creature blocking it beyond the first.)

Zelyon Sword

You may choose not to untap Zelyon Sword during your untap step.
{3}, {T}: Target creature gets +2/+0 for as long as Zelyon Sword remains tapped.

Serra Zealot

Lost Order of Jarkeld

As Lost Order of Jarkeld enters, choose an opponent.
Lost Order of Jarkeld's power and toughness are each equal to 1 plus the number of creatures the chosen player controls.

Knights of Thorn

Protection from red; banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Crusading Knight

Protection from black
Crusading Knight gets +1/+1 for each Swamp your opponents control.

Order of Leitbur

Protection from black
{W}: Order of Leitbur gains first strike until end of turn.
{W}{W}: Order of Leitbur gets +1/+0 until end of turn.

Silver Knight

Southern Paladin

{W}{W}, {T}: Destroy target red permanent.

Swords to Plowshares

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

Benalish Knight

Flash (You may cast this spell any time you could cast an instant.)
First strike (This creature deals combat damage before creatures without first strike.)

Phyrexian Crusader

First strike, protection from red and from white
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Headless Rider

Whenever Headless Rider or another nontoken Zombie you control dies, create a 2/2 black Zombie creature token.

Pentarch Paladin

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
As Pentarch Paladin enters, choose a color.
{W}{W}, {T}: Destroy target permanent of the chosen color.

Spectral Rider

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Varchild's Crusader

{0}: Varchild's Crusader can't be blocked this turn except by Walls. Sacrifice Varchild's Crusader at the beginning of the next end step.

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.

It That Rides as One

Lone Rider

First strike, lifelink
At the beginning of the end step, if you gained 3 or more life this turn, transform Lone Rider.

Lone Rider // It That Rides as One

Xiahou Dun, the One-Eyed

Horsemanship (This creature can't be blocked except by creatures with horsemanship.)
Sacrifice Xiahou Dun, the One-Eyed: Return target black card from your graveyard to your hand. Activate only during your turn, before attackers are declared.

Knight of the Mists

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
When Knight of the Mists enters, you may pay {U}. If you don't, destroy target Knight and it can't be regenerated.

Knight of the Holy Nimbus

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
If Knight of the Holy Nimbus would be destroyed, regenerate it. (Tap it, remove it from combat, and heal all damage on it.)
{2}: Knight of the Holy Nimbus can't be regenerated this turn. Only your opponents may activate this ability.

Knight of Malice

First strike (This creature deals combat damage before creatures without first strike.)
Hexproof from white (This creature can't be the target of white spells or abilities your opponents control.)
This creature gets +1/+0 as long as any player controls a white permanent.

Western Paladin

{B}{B}, {T}: Destroy target white creature.

Jerrard of the Closed Fist

Sword of the Ages

Sword of the Ages enters tapped.
{T}, Sacrifice Sword of the Ages and any number of creatures you control: Sword of the Ages deals X damage to any target, where X is the total power of the creatures sacrificed this way, then exile Sword of the Ages and those creature cards.

Paladin en-Vec

First strike, protection from black and from red (This creature deals combat damage before creatures without first strike. It can't be blocked, targeted, dealt damage, or enchanted by anything black or red.)

Marauding Knight

Protection from white
Marauding Knight gets +1/+1 for each Plains your opponents control.

Icatian Infantry

{1}: Icatian Infantry gains first strike until end of turn.
{1}: Icatian Infantry gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Stromgald Crusader

Protection from white
{B}: Stromgald Crusader gains flying until end of turn.
{B}{B}: Stromgald Crusader gets +1/+0 until end of turn.

Stromgald Cabal

{T}, Pay 1 life: Counter target white spell.

Deathless Knight

Haste
When you gain life for the first time each turn, return Deathless Knight from your graveyard to your hand.

Kjeldoran Knight

Banding (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding you control are blocking or being blocked by a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)
{1}{W}: Kjeldoran Knight gets +1/+0 until end of turn.
{W}{W}: Kjeldoran Knight gets +0/+2 until end of turn.