Undermine

Counter target spell. Its controller loses 3 life.

Mindblade Render

Whenever your opponents are dealt combat damage, if any of that damage was dealt by a Warrior, you draw a card and you lose 1 life.

Loyal Subordinate

Menace (This creature can't be blocked except by two or more creatures.)
Lieutenant — At the beginning of combat on your turn, if you control your commander, each opponent loses 3 life.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Raving Oni-Slave

When this creature enters or leaves the battlefield, you lose 3 life if you don't control a Demon.

Blacklance Paragon

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

Sygg, River Cutthroat

At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)

Daring Saboteur

{2}{U}: This creature can't be blocked this turn.
Whenever this creature deals combat damage to a player, you may draw a card. If you do, discard a card.

Court of Ambition

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.