Hagra Diabolist

Whenever Hagra Diabolist or another Ally you control enters, you may have target player lose life equal to the number of Allies you control.

Nimana Sell-Sword

Whenever Nimana Sell-Sword or another Ally you control enters, you may put a +1/+1 counter on Nimana Sell-Sword.

Agadeem Occultist

{T}: Put target creature card from an opponent's graveyard onto the battlefield under your control if its mana value is less than or equal to the number of Allies you control.

Bala Ged Thief

Whenever Bala Ged Thief or another Ally you control enters, target player reveals a number of cards from their hand equal to the number of Allies you control. You choose one of them. That player discards that card.

Swamp

Infernal Grasp

Destroy target creature. You lose 2 life.

Zulaport Cutthroat

Whenever Zulaport Cutthroat or another creature you control dies, each opponent loses 1 life and you gain 1 life.

Ambition's Cost

You draw three cards and you lose 3 life.

Aphotic Wisps

Target creature becomes black and gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)
Draw a card.

Bojuka Brigand

Bojuka Brigand can't block.
Whenever Bojuka Brigand or another Ally you control enters, you may put a +1/+1 counter on Bojuka Brigand.

Malakir Soothsayer

Cohort — {T}, Tap an untapped Ally you control: You draw a card and you lose 1 life.

Zulaport Chainmage

Cohort — {T}, Tap an untapped Ally you control: Target opponent loses 2 life.

Kalastria Healer

Rally — Whenever Kalastria Healer or another Ally you control enters, each opponent loses 1 life and you gain 1 life.