Pacifism

Enchant creature
Enchanted creature can't attack or block.

Grasping Giant

Vigilance
Whenever Grasping Giant becomes blocked by a creature, exile that creature until Grasping Giant leaves the battlefield.

Enchant creature
Enchanted creature gets +2/+2, has first strike, and is a Knight in addition to its other types. (It deals combat damage before creatures without first strike.)

Inspiring Veteran

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.

Wind-Scarred Crag

Wind-Scarred Crag enters tapped.
When Wind-Scarred Crag enters, you gain 1 life.
{T}: Add {R} or {W}.

Haktos the Unscarred

Haktos the Unscarred attacks each combat if able.
As Haktos enters, choose 2, 3, or 4 at random.
Haktos has protection from each mana value other than the chosen number.

Mountain

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

Plains

Scorching Dragonfire

Scorching Dragonfire deals 3 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

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}

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.

Fireborn Knight

Double strike
{R/W}{R/W}{R/W}{R/W}: Fireborn Knight gets +1/+1 until end of turn.

Infuriate

Target creature gets +3/+2 until end of turn.

Temple of Triumph

Temple of Triumph enters tapped.
When Temple of Triumph enters, scry 1.
{T}: Add {R} or {W}.

Venerable Knight

When Venerable Knight dies, put a +1/+1 counter on target Knight you control.

Youthful Knight

Short Sword

Equipped creature gets +1/+1.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Weaselback Redcap

{1}{R}: Weaselback Redcap gets +2/+0 until end of turn.

Basri's Lieutenant

Vigilance, protection from multicolored
When Basri's Lieutenant enters, put a +1/+1 counter on target creature you control.
Whenever Basri's Lieutenant or another creature you control dies, if it had a +1/+1 counter on it, create a 2/2 white Knight creature token with vigilance.

Basri's Acolyte

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
When Basri's Acolyte enters, put a +1/+1 counter on each of up to two other target creatures you control.

Worthy Knight

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

Dizzying Swoop

Tap up to two target creatures. (Then exile this card. You may cast the creature later from exile.)