Blacksnag Buzzard

Flying
Blacksnag Buzzard enters with a +1/+1 counter on it if a creature died this turn.
Plot {1}{B} (You may pay {1}{B} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

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.

Phyresis

Enchant creature
Enchanted creature has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Bone Picker

This spell costs {3} less to cast if a creature died this turn.
Flying, deathtouch

Murder

Sultai Scavenger

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Flying

Grievous Wound

Enchant player
Enchanted player can't gain life.
Whenever enchanted player is dealt damage, they lose half their life, rounded up.

Swamp

Raven of Fell Omens

Flying
Whenever you commit a crime, each opponent loses 1 life and you gain 1 life. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Carrion Screecher

Dunland Crebain

Flying
When Dunland Crebain enters, amass Orcs 2. (Put two +1/+1 counters on an Army you control. It's also an Orc. If you don't control an Army, create a 0/0 black Orc Army creature token first.)

Bastion of Remembrance

When Bastion of Remembrance enters, create a 1/1 white Human Soldier creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.