Ordeal of Heliod

Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice this Aura.
When you sacrifice this Aura, you gain 10 life.

Evolving Wilds

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

Ogre Errant

Whenever this creature attacks, another target attacking Knight gains menace until end of turn. (It can't be blocked except by two or more creatures.)

Crystal Slipper

Equipped creature gets +1/+0 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Raging Redcap

Double strike (This creature deals both first-strike and regular combat damage.)

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Terramorphic Expanse

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Vivid Crag

This land enters tapped with two charge counters on it.
{T}: Add {R}.
{T}, Remove a charge counter from this land: Add one mana of any color.

Cosmotronic Wave

Cosmotronic Wave deals 1 damage to each creature your opponents control. Creatures your opponents control can't block this turn.

Syr Alin, the Lion's Claw

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Syr Alin attacks, other creatures you control get +1/+1 until end of turn.

Plains

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

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Brimstone Trebuchet

Defender, reach
{T}: This creature deals 1 damage to each opponent.
Whenever a Knight you control enters, untap this creature.

Dizzying Swoop

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

Ardenvale Tactician

Ardenvale Tactician // Dizzying Swoop

Outflank

Outflank deals damage to target attacking or blocking creature equal to the number of creatures you control.

Mountain

Weaselback Redcap

{1}{R}: This creature gets +2/+0 until end of turn.

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.)

Battlefield Forge

{T}: Add {C}.
{T}: Add {R} or {W}. This land deals 1 damage to you.

Inspiring Captain

When this creature enters, creatures you control get +1/+1 until end of turn.

Shining Armor

Flash
When this Equipment enters, attach it to target Knight you control.
Equipped creature gets +0/+2 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Acclaimed Contender

When this creature 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.