Brimstone Trebuchet

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

Weaselback Redcap

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

Joust

Choose target creature you control and target creature you don't control. The creature you control gets +2/+1 until end of turn if it's a Knight. Then those creatures fight each other. (Each deals damage equal to its power to the other.)

Worthy Knight

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

Syr Carah, the Bold

Whenever Syr Carah, the Bold or an instant or sorcery spell you control deals damage to a player, exile the top card of your library. You may play that card this turn.
{T}: Syr Carah deals 1 damage to any target.

Venerable Knight

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

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.)

Stormfist Crusader

Menace
At the beginning of your upkeep, each player draws a card and loses 1 life.

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

Jousting Dummy

{3}: Jousting Dummy gets +1/+0 until end of turn.

Raging Redcap

Syr Alin, the Lion's Claw

First strike
Whenever Syr Alin, the Lion's Claw attacks, other creatures you control get +1/+1 until end of turn.

Plains

Steelclaw Lance

Equipped creature gets +2/+2.
Equip Knight {1}
Equip {3}

Swamp

Tournament Grounds

{T}: Add {C}.
{T}: Add {R}, {W}, or {B}. Spend this mana only to cast a Knight or Equipment spell.