Weakness

Enchant creature
Enchanted creature gets -2/-1.

Throne of Bone

Whenever a player casts a black spell, you may pay {1}. If you do, you gain 1 life.

Bog Imp

Flying (This creature can't be blocked except by creatures with flying or reach.)

Sinkhole

Erg Raiders

At the beginning of your end step, if Erg Raiders didn't attack this turn, Erg Raiders deals 2 damage to you unless it came under your control this turn.

Sol Ring

Demonic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Icy Manipulator

{1}, {T}: Tap target artifact, creature, or land.

Evil Presence

Bog Wraith

Swampwalk (This creature can't be blocked as long as defending player controls a Swamp.)

Lesser Werewolf

{B}: If Lesser Werewolf's power is 1 or more, it gets -1/-0 until end of turn and put a -0/-1 counter on target creature blocking or blocked by Lesser Werewolf. Activate only during the declare blockers step.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Paralyze

Enchant creature
When Paralyze enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {4}. If the player does, untap the creature.

Pestilence

At the beginning of the end step, if no creatures are on the battlefield, sacrifice Pestilence.
{B}: Pestilence deals 1 damage to each creature and each player.

Swamp

Underworld Dreams

Whenever an opponent draws a card, Underworld Dreams deals 1 damage to that player.

Oubliette

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Nightmare

Flying (This creature can't be blocked except by creatures with flying or reach.)
Nightmare's power and toughness are each equal to the number of Swamps you control.

Unholy Strength

Enchant creature
Enchanted creature gets +2/+1.

Library of Alexandria

{T}: Add {C}.
{T}: Draw a card. Activate only if you have exactly seven cards in hand.

Chaos Orb

{1}, {T}: If Chaos Orb is on the battlefield, flip Chaos Orb onto the battlefield from a height of at least one foot. If Chaos Orb turns over completely at least once during the flip, destroy all nontoken permanents it touches. Then destroy Chaos Orb.

Dark Ritual

Juzám Djinn

At the beginning of your upkeep, Juzám Djinn deals 1 damage to you.

Hasran Ogress

Whenever Hasran Ogress attacks, it deals 3 damage to you unless you pay {2}.

Frozen Shade

{B}: Frozen Shade gets +1/+1 until end of turn.

Su-Chi

Order of the Ebon Hand

Protection from white
{B}: Order of the Ebon Hand gains first strike until end of turn.
{B}{B}: Order of the Ebon Hand gets +1/+0 until end of turn.

Drain Life

Spend only black mana on X.
Drain Life deals X damage to any target. You gain life equal to the damage dealt, but not more life than the player's life total before the damage was dealt, the planeswalker's loyalty before the damage was dealt, or the creature's toughness.

Mishra's Factory

{T}: Add {C}.
{1}: Mishra's Factory becomes a 2/2 Assembly-Worker artifact creature until end of turn. It's still a land.
{T}: Target Assembly-Worker creature gets +1/+1 until end of turn.

Terror

Destroy target nonartifact, nonblack creature. It can't be regenerated.

Spirit Shackle

Enchant creature
Whenever enchanted creature becomes tapped, put a -0/-2 counter on it.

Strip Mine

{T}: Add {C}.
{T}, Sacrifice Strip Mine: Destroy target land.

Guardian Beast

As long as Guardian Beast is untapped, noncreature artifacts you control can't be enchanted, they have indestructible, and other players can't gain control of them. This effect doesn't remove Auras already attached to those artifacts.