Silver Knight

Ruins of Trokair

Ruins of Trokair enters tapped.
{T}: Add {W}.
{T}, Sacrifice Ruins of Trokair: Add {W}{W}.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Plains

Warrior en-Kor

{0}: The next 1 damage that would be dealt to Warrior en-Kor this turn is dealt to target creature you control instead.

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.

Shared Triumph

As Shared Triumph enters, choose a creature type.
Creatures of the chosen type get +1/+1.

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.

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.)

Veteran Cavalier

Vigilance (Attacking doesn't cause this creature to tap.)

Mirran Crusader

Double strike, protection from black and from green

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.

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

Leonin Skyhunter

Crusade

Knight of Meadowgrain

First strike
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Spectral Rider

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