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

Rakdos Signet

Maddening Hex

Enchant player
Whenever enchanted player casts a noncreature spell, roll a d6. Maddening Hex deals damage to that player equal to the result. Then attach Maddening Hex to another one of your opponents chosen at random.

Grim Guardian

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

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Steam Vents

({T}: Add {U} or {R}.)
As Steam Vents enters, you may pay 2 life. If you don't, it enters tapped.

Bedevil

Destroy target artifact, creature, or planeswalker.

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.

Feed the Swarm

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

Mirrormade

You may have Mirrormade enter as a copy of any artifact or enchantment on the battlefield.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Curse of Bloodletting

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

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.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Terminate

Destroy target creature. It can't be regenerated.

Paradox Haze

Enchant player
At the beginning of enchanted player's first upkeep each turn, that player gets an additional upkeep step after this step.

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

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Curse of Death's Hold

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

Maestros Theater

When Maestros Theater enters, sacrifice it. When you do, search your library for a basic Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle and you gain 1 life.

Curse of Unbinding

Enchant player
At the beginning of enchanted player's upkeep, that player reveals cards from the top of their library until they reveal a creature card. Put that card onto the battlefield under your control. That player puts the rest of the revealed cards into their graveyard.

Talisman of Creativity

{T}: Add {C}.
{T}: Add {U} or {R}. Talisman of Creativity deals 1 damage to you.

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 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.

Sol Ring

Vandalblast

Destroy target artifact you don't control.
Overload {4}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Protean Thaumaturge

Constellation — Whenever an enchantment you control enters, you may have Protean Thaumaturge become a copy of another target creature, except it has this ability.

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.")

Counterspell

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Curse of Verbosity

Enchant player
Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Curse of the Swine

Exile X target creatures. For each creature exiled this way, its controller creates a 2/2 green Boar creature token.

Crystal Chimes

{3}, {T}, Sacrifice Crystal Chimes: Return all enchantment cards from your graveyard to your hand.

Crumbling Necropolis

Crumbling Necropolis enters tapped.
{T}: Add {U}, {B}, or {R}.

Dragonskull Summit

Dragonskull Summit enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Claws of Gix

{1}, Sacrifice a permanent: You gain 1 life.

Morphic Pool

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

Sphinx of the Second Sun

Flying
At the beginning of each of your postcombat main phases, there is an additional beginning phase after this phase. (The beginning phase includes the untap, upkeep, and draw steps.)

Talisman of Dominance

{T}: Add {C}.
{T}: Add {U} or {B}. Talisman of Dominance deals 1 damage to you.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

Braids, Arisen Nightmare

At the beginning of your end step, you may sacrifice an artifact, creature, enchantment, land, or planeswalker. If you do, each opponent may sacrifice a permanent that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Negate

Curse of Echoes

Enchant player
Whenever enchanted player casts an instant or sorcery spell, each other player may copy that spell and may choose new targets for the copy they control.

Bitterheart Witch

Deathtouch
When Bitterheart Witch dies, you may search your library for a Curse card, put it onto the battlefield attached to target player, then shuffle.

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.

Curse of the Restless Dead

Enchant player
Whenever a land enchanted player controls enters, you create a 2/2 black Zombie creature token with decayed. (It can't block. When it attacks, sacrifice it at end of combat.)

Demonic Tutor

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

Xander's Lounge

({T}: Add {U}, {B}, or {R}.)
Xander's Lounge enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Sulfur Falls

Sulfur Falls enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Lynde, Cheerful Tormentor

Deathtouch
Whenever a Curse is put into your graveyard from the battlefield, return it to the battlefield attached to you at the beginning of the next end step.
At the beginning of your upkeep, you may attach a Curse attached to you to one of your opponents. If you do, draw two cards.

Swamp

Arcane Signet

Reliquary Tower

You have no maximum hand size.
{T}: Add {C}.

Doomwake Giant

Constellation — Whenever Doomwake Giant or another enchantment you control enters, creatures your opponents control get -1/-1 until end of turn.

Mountain

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Izzet Signet

Curse of Stalked Prey

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

Thoughtrender Lamia

Constellation — Whenever Thoughtrender Lamia or another enchantment you control enters, each opponent discards a card.

Bothersome Quasit

Menace
Goaded creatures your opponents control can't block.
Whenever you cast a noncreature spell, goad target creature an opponent controls. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Cruel Reality

Enchant player
At the beginning of enchanted player's upkeep, that player sacrifices a creature or planeswalker. If the player can't, they lose 5 life.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Talisman of Indulgence

{T}: Add {C}.
{T}: Add {B} or {R}. Talisman of Indulgence deals 1 damage to you.

Curse of Surveillance

Enchant player
At the beginning of enchanted player's upkeep, any number of target players other than that player each draw cards equal to the number of Curses attached to that player.

Dimir Signet

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters tapped unless you control two or more basic lands.

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 the Nightly Hunt

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

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Terramorphic Expanse

{T}, Sacrifice Terramorphic Expanse: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Drowned Catacomb

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Torment of Scarabs

Enchant player
At the beginning of enchanted player's upkeep, that player loses 3 life unless they sacrifice a nonland permanent or discard a card.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Island

Training Center

Training Center enters tapped unless you have two or more opponents.
{T}: Add {U} or {R}.

Curse of Shallow Graves

Enchant player
Whenever a player attacks enchanted player with one or more creatures, that attacking player may create a tapped 2/2 black Zombie creature token.

Curse of Disturbance

Enchant player
Whenever enchanted player is attacked, create a 2/2 black Zombie creature token. Each opponent attacking that player does the same.

Trespasser's Curse

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

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Clever Impersonator

You may have Clever Impersonator enter as a copy of any nonland permanent on the battlefield.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

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.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Agent of Erebos

Constellation — Whenever Agent of Erebos or another enchantment you control enters, exile target player's graveyard.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.