Whisper of the Dross

Target creature gets -1/-1 until end of turn. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Outlaw Medic

Lifelink
When Outlaw Medic dies, draw a card.

Silumgar Scavenger

Flying
Exploit (When this creature enters, you may sacrifice a creature.)
Whenever another creature you control dies, put a +1/+1 counter on Silumgar Scavenger. It gains haste until end of turn if it exploited that creature.

Tragic Slip

Target creature gets -1/-1 until end of turn.
Morbid — That creature gets -13/-13 until end of turn instead if a creature died this turn.

Swamp

Novice Occultist

When Novice Occultist dies, you draw a card and you lose 1 life.

Feign Death

Until end of turn, target creature gains "When this creature dies, return it to the battlefield tapped under its owner's control with a +1/+1 counter on it."

Star Pupil

Star Pupil enters with a +1/+1 counter on it.
When Star Pupil dies, put its counters on target creature you control.

Plains

Edge of the Divinity

Enchant creature
As long as enchanted creature is white, it gets +1/+2.
As long as enchanted creature is black, it gets +2/+1.

Cartel Aristocrat

Sacrifice another creature: Cartel Aristocrat gains protection from the color of your choice until end of turn.

Undying Evil

Target creature gains undying until end of turn. (When it dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Beckon Apparition

Exile target card from a graveyard. Create a 1/1 white and black Spirit creature token with flying.

Nightsky Mimic

Whenever you cast a spell that's both white and black, Nightsky Mimic has base power and toughness 4/4 until end of turn and gains flying until end of turn.

Elder Cathar

When Elder Cathar dies, put a +1/+1 counter on target creature you control. If that creature is a Human, put two +1/+1 counters on it instead.

Mortician Beetle

Whenever a player sacrifices a creature, you may put a +1/+1 counter on Mortician Beetle.

Falkenrath Torturer

Sacrifice a creature: Falkenrath Torturer gains flying until end of turn. If the sacrificed creature was a Human, put a +1/+1 counter on Falkenrath Torturer.

Martyr for the Cause

When Martyr for the Cause dies, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Deadly Dispute

As an additional cost to cast this spell, sacrifice an artifact or creature.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Enduring Bondwarden

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
When this creature dies, put its counters on target creature you control.