Unsummon

Return target creature to its owner's hand.

Dread Warlock

Dread Warlock can't be blocked except by black creatures.

Doom Blade

Corrupted Conscience

Enchant creature
You control enchanted 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.)

Vault Skirge

({B/P} can be paid with either {B} or 2 life.)
Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Phyrexian Digester

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Vampire Nighthawk

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Lifelink (Damage dealt by this creature also causes you to gain that much life.)

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Silver Myr

Go for the Throat

Parasitic Strix

Flying
When Parasitic Strix enters, if you control a black permanent, target player loses 2 life and you gain 2 life.

Diminish

Target creature has base power and toughness 1/1 until end of turn.

Swamp

Plague Stinger

Flying
Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

Island

Mask of Riddles

Equipped creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
Whenever equipped creature deals combat damage to a player, you may draw a card.
Equip {2}

Executioner's Capsule

{1}{B}, {T}, Sacrifice Executioner's Capsule: Destroy target nonblack creature.

Flayer Husk

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +1/+1.
Equip {2}

Corpse Cur

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
When Corpse Cur enters, you may return target creature card with infect from your graveyard to your hand.

Spellskite

{U/P}: Change a target of target spell or ability to Spellskite. ({U/P} can be paid with either {U} or 2 life.)

Gargoyle Castle

{T}: Add {C}.
{5}, {T}, Sacrifice Gargoyle Castle: Create a 3/4 colorless Gargoyle artifact creature token with flying.

Leaden Myr

Grafted Exoskeleton

Equipped creature gets +2/+2 and has infect. (It deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Grafted Exoskeleton becomes unattached from a permanent, sacrifice that permanent.
Equip {2}

Contagious Nim

Phantom Warrior

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Creeping Tar Pit

Creeping Tar Pit enters tapped.
{T}: Add {U} or {B}.
{1}{U}{B}: Creeping Tar Pit becomes a 3/2 blue and black Elemental creature until end of turn and can't be blocked this turn. It's still a land.

Ichorclaw Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Whenever Ichorclaw Myr becomes blocked, it gets +2/+2 until end of turn.

Tidehollow Strix

Flying
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Aether Figment

Kicker {3} (You may pay an additional {3} as you cast this spell.)
Aether Figment can't be blocked.
If Aether Figment was kicked, it enters with two +1/+1 counters on it.

Narcolepsy

Enchant creature
At the beginning of each upkeep, if enchanted creature is untapped, tap it.