Weight of the Underworld

Enchant creature
Enchanted creature gets -3/-2.

Banewasp Affliction

Enchant creature
When enchanted creature dies, that creature's controller loses life equal to its toughness.

Torture

Enchant creature
{1}{B}: Put a -1/-1 counter on enchanted creature.

Shrine Steward

When Shrine Steward enters, you may search your library for an Aura or Shrine card, reveal it, put it into your hand, then shuffle.

Hateful Eidolon

Lifelink
Whenever an enchanted creature dies, draw a card for each Aura you controlled that was attached to it.

Parasitic Impetus

Enchant creature
Enchanted creature gets +2/+2 and is goaded. (It attacks each combat if able and attacks a player other than you if able.)
Whenever enchanted creature attacks, its controller loses 2 life and you gain 2 life.

Unhallowed Pact

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control.

Yoke of the Damned

Enchant creature
When a creature dies, destroy enchanted creature.

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Baleful Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Enchanted creature gets +1/+1 and has deathtouch.

Parallax Dementia

Enchant creature
Fading 1 (This enchantment enters with one fade counter on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
Enchanted creature gets +3/+2.
When Parallax Dementia leaves the battlefield, destroy enchanted creature. That creature can't be regenerated.

Feast of Dreams

Destroy target enchanted creature or enchantment creature.

Demonic Vigor

Enchant creature
Enchanted creature gets +1/+1.
When enchanted creature dies, return that card to its owner's hand.

Grave Servitude

You may cast Grave Servitude as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
Enchant creature
Enchanted creature gets +3/-1 and is black.

Ancestral Vengeance

Enchant creature
When Ancestral Vengeance enters, put a +1/+1 counter on target creature you control.
Enchanted creature gets -1/-1.

Clinging Darkness

Enchant creature
Enchanted creature gets -4/-1.

Unholy Indenture

Enchant creature
When enchanted creature dies, return that card to the battlefield under your control with a +1/+1 counter on it.

Feed the Swarm

Destroy target creature or enchantment an opponent controls. You lose life equal to that permanent's mana value.

Crippling Blight

Enchant creature
Enchanted creature gets -1/-1 and can't block.

World-Weary

Enchant creature
Enchanted creature gets -4/-4.
Basic landcycling {1}{B} ({1}{B}, Discard this card: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.)

Cursed Flesh

Enchant creature
Enchanted creature gets -1/-1 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)

Death's Approach

Enchant creature
Enchanted creature gets -X/-X, where X is the number of creature cards in its controller's graveyard.

Grim Guardian

Constellation — Whenever Grim Guardian or another enchantment you control enters, each opponent loses 1 life.

Parasitic Implant

Enchant creature
At the beginning of your upkeep, enchanted creature's controller sacrifices it and you create a 1/1 colorless Phyrexian Myr artifact creature token.

Ghoulflesh

Enchant creature
Enchanted creature gets -1/-1 and is a black Zombie in addition to its other colors and types.

Crown of Suspicion

Enchant creature
Enchanted creature gets +2/-1.
Sacrifice Crown of Suspicion: Enchanted creature and other creatures that share a creature type with it get +2/-1 until end of turn.

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Kagemaro's Clutch

Enchant creature
Enchanted creature gets -X/-X, where X is the number of cards in your hand.

Mire's Grasp

Enchant creature
Enchanted creature gets -3/-3.

Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters, you may return Dragon Shadow from your graveyard to the battlefield attached to that creature.

Coils of the Medusa

Enchant creature
Enchanted creature gets +1/-1.
Sacrifice Coils of the Medusa: Destroy all non-Wall creatures blocking enchanted creature.

Mogis's Favor

Enchant creature
Enchanted creature gets +2/-1.
Escape—{2}{B}, Exile two other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Maggot Therapy

Flash
Enchant creature
Enchanted creature gets +2/-2.

Phyrexian Boon

Enchant creature
Enchanted creature gets +2/+1 as long as it's black. Otherwise, it gets -1/-2.

Failed Conversion

Enchant creature
Enchanted creature gets -4/-4.
When enchanted creature dies, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Quag Sickness

Enchant creature
Enchanted creature gets -1/-1 for each Swamp you control.

Enfeeblement

Enchant creature (Target a creature as you cast this. This card enters attached to that creature.)
Enchanted creature gets -2/-2.

Twisted Experiment

Enchant creature
Enchanted creature gets +3/-1.

Patriarch's Desire

Enchant creature
Enchanted creature gets +2/-2.
Threshold — Enchanted creature gets an additional +2/-2 as long as seven or more cards are in your graveyard.

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Viper's Kiss

Enchant creature
Enchanted creature gets -1/-1, and its activated abilities can't be activated.

Necromancer's Magemark

Enchant creature
Creatures you control that are enchanted get +1/+1.
If a creature you control that's enchanted would die, return it to its owner's hand instead.

Sicken

Enchant creature
Enchanted creature gets -1/-1.
Cycling {2} ({2}, Discard this card: Draw a card.)

Boon of Emrakul

Enchant creature
Enchanted creature gets +3/-3.

Dying Wail

Enchant creature
When enchanted creature dies, target player discards two cards.

Feebleness

Flash
Enchant creature
Enchanted creature gets -2/-1.

Nyxborn Eidolon

Bestow {4}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Enchanted creature gets +2/+1.

Kaya's Ghostform

Enchant creature or planeswalker you control
When enchanted permanent dies or is put into exile, return that card to the battlefield under your control.

Despondency

Enchant creature
Enchanted creature gets -2/-0.
When Despondency is put into a graveyard from the battlefield, return Despondency to its owner's hand.

Weakness

Enchant creature
Enchanted creature gets -2/-1.

Lingering Death

Enchant creature
At the beginning of the end step of enchanted creature's controller, that player sacrifices that creature.

Gift of Fangs

Enchant creature
Enchanted creature gets +2/+2 as long as it's a Vampire. Otherwise, it gets -2/-2.

Debilitating Injury

Nyx Infusion

Enchant creature
Enchanted creature gets +2/+2 as long as it's an enchantment. Otherwise, it gets -2/-2.

Grisly Transformation

Enchant creature
When Grisly Transformation enters, draw a card.
Enchanted creature has intimidate. (It can't be blocked except by artifact creatures and/or creatures that share a color with it.)