Blacklance Paragon

Flash
When Blacklance Paragon enters, target Knight gains deathtouch and lifelink until end of turn.

Elite Headhunter

Menace (This creature can't be blocked except by two or more creatures.)
{B/R}{B/R}{B/R}, Sacrifice another creature or an artifact: Elite Headhunter deals 2 damage to target creature or planeswalker.

Barrow Witches

When Barrow Witches enters, return target Knight card from your graveyard to your hand.

Belle of the Brawl

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Belle of the Brawl attacks, other Knights you control get +1/+0 until end of turn.