Curse of Thirst

Enchant player
At the beginning of enchanted player's upkeep, Curse of Thirst deals damage to that player equal to the number of Curses attached to them.

Curse of Vitality

Enchant player
Whenever enchanted player is attacked, you gain 2 life. Each opponent attacking that player does the same.

Ghen, Arcanum Weaver

{R}{W}{B}, {T}, Sacrifice an enchantment: Return target enchantment card from your graveyard to the battlefield.

Blight Sickle

Equipped creature gets +1/+0 and has wither. (It deals damage to creatures in the form of -1/-1 counters.)
Equip {2}

Godsend

Equipped creature gets +3/+3.
Whenever equipped creature blocks or becomes blocked by one or more creatures, you may exile one of those creatures.
Your opponents can't cast spells with the same name as a card exiled with Godsend.
Equip {3}

Blazing Torch

Equipped creature can't be blocked by Vampires or Zombies.
Equipped creature has "{T}, Sacrifice Blazing Torch: Blazing Torch deals 2 damage to any target."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Leeching Lurker

Lifelink
Nightbound (If a player casts at least two spells during their own turn, it becomes day next turn.)

Curse of Leeches

Enchant player
As this permanent transforms into Curse of Leeches, attach it to a player.
At the beginning of enchanted player's upkeep, they lose 1 life and you gain 1 life.
Daybound (If a player casts no spells during their own turn, it becomes night next turn.)

Curse of Leeches // Leeching Lurker

Curse of Wizardry

As Curse of Wizardry enters, choose a color.
Whenever a player casts a spell of the chosen color, that player loses 1 life.

Blackblade Reforged

Equipped creature gets +1/+1 for each land you control.
Equip legendary creature {3}
Equip {7}

Curse of Shaken Faith

Enchant player
Whenever enchanted player casts a spell other than the first spell they cast each turn or copies a spell, Curse of Shaken Faith deals 2 damage to them.

Curse of Misfortunes

Enchant player
At the beginning of your upkeep, you may search your library for a Curse card that doesn't have the same name as a Curse attached to enchanted player, put it onto the battlefield attached to that player, then shuffle.

Have

Wyleth, Soul of Steel

Trample
Whenever Wyleth, Soul of Steel attacks, draw a card for each Aura and Equipment attached to it.

Curse of Marit Lage

When Curse of Marit Lage enters, tap all Islands.
Islands don't untap during their controllers' untap steps.

Commander's Plate

Equipped creature gets +3/+3 and has protection from each color that's not in your commander's color identity.
Equip commander {3}
Equip {5}

Curse of the Forsaken

Enchant player
Whenever a creature attacks enchanted player, its controller gains 1 life.

Curse of Chaos

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may discard a card. If the player does, they draw a card.

Curse of Opulence

Enchant player
Whenever enchanted player is attacked, create a Gold token. Each opponent attacking that player does the same. (A Gold token is an artifact with "Sacrifice this artifact: Add one mana of any color.")

Bonehoard

Living weapon (When this Equipment enters, create a 0/0 black Phyrexian Germ creature token, then attach this to it.)
Equipped creature gets +X/+X, where X is the number of creature cards in all graveyards.
Equip {2}

Curse of Exhaustion

Enchant player
Enchanted player can't cast more than one spell each turn.

Swamp

Deathrender

Equipped creature gets +2/+2.
Whenever equipped creature dies, you may put a creature card from your hand onto the battlefield and attach Deathrender to it.
Equip {2}

Echo Circlet

Equipped creature can block an additional creature each combat.
Equip {1}

Plains

Trespasser's Curse

Enchant player
Whenever a creature enchanted player controls enters, that player loses 1 life and you gain 1 life.

Banshee's Blade

Equipped creature gets +1/+1 for each charge counter on Banshee's Blade.
Whenever equipped creature deals combat damage, put a charge counter on Banshee's Blade.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Curse of the Pierced Heart

Enchant player
At the beginning of enchanted player's upkeep, Curse of the Pierced Heart deals 1 damage to that player or a planeswalker that player controls.

Infectious Curse

Enchant player
Spells you cast that target enchanted player cost {1} less to cast.
At the beginning of enchanted player's upkeep, that player loses 1 life and you gain 1 life.

Accursed Witch

Spells your opponents cast that target Accursed Witch cost {1} less to cast.
When Accursed Witch dies, return it to the battlefield transformed under your control attached to target opponent.

Accursed Witch // Infectious Curse

Curse of Oblivion

Enchant player
At the beginning of enchanted player's upkeep, that player exiles two cards from their graveyard.

Curse of Conformity

Enchant player
Nonlegendary creatures enchanted player controls have base power and toughness 3/3 and lose all creature types.

Blinding Powder

Equipped creature has "Unattach Blinding Powder: Prevent all combat damage that would be dealt to this creature this turn."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Mountain

Curse of the Nightly Hunt

Enchant player
Creatures enchanted player controls attack each combat if able.

Argentum Armor

Equipped creature gets +6/+6.
Whenever equipped creature attacks, destroy target permanent.
Equip {6}

Curse of Hospitality

Enchant player
Creatures attacking enchanted player have trample.
Whenever a creature deals combat damage to enchanted player, that player exiles the top card of their library. Until end of turn, that creature's controller may play that card and they may spend mana as though it were mana of any color to cast that spell.

Cursed Totem

Activated abilities of creatures can't be activated.

Killian, Ink Duelist

Lifelink
Menace (This creature can't be blocked except by two or more creatures.)
Spells you cast that target a creature cost {2} less to cast.

Assault Suit

Equipped creature gets +2/+2, has haste, can't attack you or planeswalkers you control, and can't be sacrificed.
At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it.
Equip {3}

Brawler's Plate

Equipped creature gets +2/+2 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Conqueror's Flail

Equipped creature gets +1/+1 for each color among permanents you control.
As long as Conqueror's Flail is attached to a creature, your opponents can't cast spells during your turn.
Equip {2}

Battlemage's Bracers

Equipped creature has haste.
Whenever an ability of equipped creature is activated, if it isn't a mana ability, you may pay {1}. If you do, copy that ability. You may choose new targets for the copy.
Equip {2}

Champion's Helm

Equipped creature gets +2/+2.
As long as equipped creature is legendary, it has hexproof. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Cursebreak

Destroy target enchantment. You gain 2 life.

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Explorer's Scope

Whenever equipped creature attacks, look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Dancing Sword

Equipped creature gets +2/+1.
When equipped creature dies, you may have Dancing Sword become a 2/1 Construct artifact creature with flying and ward {1}. If you do, it isn't an Equipment.
Equip {1}

Bladed Bracers

Equipped creature gets +1/+1.
As long as equipped creature is a Human or an Angel, it has vigilance.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Diviner's Wand

Equipped creature has "Whenever you draw a card, this creature gets +1/+1 and gains flying until end of turn" and "{4}: Draw a card."
Whenever a Wizard creature enters, you may attach Diviner's Wand to it.
Equip {3}

Curse of Fool's Wisdom

Enchant player
Whenever enchanted player draws a card, they lose 2 life and you gain 2 life.
Madness {3}{B} (If you discard this card, discard it into exile. When you do, cast it for its madness cost or put it into your graveyard.)

Curse of Stalked Prey

Enchant player
Whenever a creature deals combat damage to enchanted player, put a +1/+1 counter on that creature.

Blazing Sunsteel

Equipped creature gets +1/+0 for each opponent you have.
Whenever equipped creature is dealt damage, it deals that much damage to any target.
Equip {4}

Exotic Curse

Enchant creature
Domain — Enchanted creature gets -1/-1 for each basic land type among lands you control.

Arvad the Cursed

Deathtouch, lifelink
Other legendary creatures you control get +2/+2.

Withengar Unbound

Flying, intimidate, trample (A creature with intimidate can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a player loses the game, put thirteen +1/+1 counters on Withengar Unbound.

Elbrus, the Binding Blade

Equipped creature gets +1/+0.
When equipped creature deals combat damage to a player, unattach Elbrus, the Binding Blade, then transform it.
Equip {1}

Elbrus, the Binding Blade // Withengar Unbound

Curse of the Cabal

Target player sacrifices half the permanents they control of their choice, rounded down.
Suspend 2—{2}{B}{B} (Rather than cast this card from your hand, you may pay {2}{B}{B} and exile it with two time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost.)
At the beginning of each player's upkeep, if Curse of the Cabal is suspended, that player may sacrifice a permanent of their choice. If the player does, put two time counters on Curse of the Cabal.

Curse of Death's Hold

Enchant player
Creatures enchanted player controls get -1/-1.

Curse of Obsession

Enchant player
At the beginning of enchanted player's draw step, that player draws two additional cards.
At the beginning of enchanted player's end step, that player discards their hand.

Curse of Vengeance

Enchant player
Whenever enchanted player casts a spell, put a spite counter on Curse of Vengeance.
When enchanted player loses the game, you gain X life and draw X cards, where X is the number of spite counters on Curse of Vengeance.