Gurmag Rakshasa

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, target creature an opponent controls gets -2/-2 until end of turn and target creature you control gets +2/+2 until end of turn.

Hundred-Battle Veteran

As long as there are three or more different kinds of counters among creatures you control, this creature gets +2/+4.
You may cast this card from your graveyard. If you do, it enters with a finality counter on it. (If a creature with a finality counter on it would die, exile it instead.)

Kin-Tree Nurturer

Spirit

Lifelink
When this creature enters, it endures 1. (Put a +1/+1 counter on it or create a 1/1 white Spirit creature token.)

Krumar Initiate

{X}{B}, {T}, Pay X life: This creature endures X. Activate only as a sorcery. (Put X +1/+1 counters on it or create an X/X white Spirit creature token.)

Nightblade Brigade

Warrior

Deathtouch
Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)
When this creature enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Qarsi Revenant

Flying, deathtouch, lifelink
Renew — {2}{B}, Exile this card from your graveyard: Put a flying counter, a deathtouch counter, and a lifelink counter on target creature. Activate only as a sorcery.

Rot-Curse Rakshasa

Trample
Decayed (This creature can't block. When it attacks, sacrifice it at end of combat.)
Renew — {X}{B}{B}, Exile this card from your graveyard: Put a decayed counter on each of X target creatures. Activate only as a sorcery.

Salt Road Skirmish

Destroy target creature. Create two 1/1 red Warrior creature tokens. They gain haste until end of turn. Sacrifice them at the beginning of the next end step.

Sandskitter Outrider

Menace (This creature can't be blocked except by two or more creatures.)
When this creature enters, it endures 2. (Put two +1/+1 counters on it or create a 2/2 white Spirit creature token.)

Dragonback Lancer

Flying
Mobilize 1 (Whenever this creature attacks, create a tapped and attacking 1/1 red Warrior creature token. Sacrifice it at the beginning of the next end step.)

Scavenger Regent

Exude Toxin

Each non-Dragon creature gets -X/-X until end of turn. (Then shuffle this card into its owner's library.)

Scavenger Regent // Exude Toxin

The Sibsig Ceremony

Zombie Druid

Creature spells you cast cost {2} less to cast.
Whenever a creature you control enters, if you cast it, destroy that creature, then create a 2/2 black Zombie Druid creature token.

Sidisi, Regent of the Mire

{T}, Sacrifice a creature you control with mana value X other than Sidisi: Return target creature card with mana value X plus 1 from your graveyard to the battlefield. Activate only as a sorcery.

Sinkhole Surveyor

Flying
Whenever this creature attacks, you lose 1 life and this creature endures 1. (Put a +1/+1 counter on it or create a 1/1 white Spirit creature token.)

Strategic Betrayal

Target opponent exiles a creature they control and their graveyard.

Unburied Earthcarver

{2}, Sacrifice another creature: Put a +1/+1 counter on this creature.

Tarkir: Dragonstorm