Blasphemous Edict

You may pay {B} rather than pay this spell's mana cost if there are thirteen or more creatures on the battlefield.
Each player sacrifices thirteen creatures of their choice.

Gonti, Night Minister

Whenever a player casts a spell they don't own, that player creates a Treasure token.
Whenever a creature deals combat damage to one of your opponents, its controller looks at the top card of that opponent's library and exiles it face down. They may play that card for as long as it remains exiled. Mana of any type can be spent to cast a spell this way.

Siphon Insight

Look at the top two cards of target opponent's library. Exile one of them face down and put the other on the bottom of that library. You may play the exiled card for as long as it remains exiled, and you may spend mana as though it were mana of any color to cast that spell.
Flashback {1}{U}{B}

Chaos Shrine's Black Crystal

Whenever a nontoken creature you control dies, exile it.
At the beginning of your upkeep, you may put a creature card exiled with Chaos Shrine's Black Crystal onto the battlefield under your control with a finality counter on it.

Breach the Multiverse

Each player mills ten cards. For each player, choose a creature or planeswalker card in that player's graveyard. Put those cards onto the battlefield under your control. Then each creature you control becomes a Phyrexian in addition to its other types.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Gloomlake Verge

{T}: Add {U}.
{T}: Add {B}. Activate only if you control an Island or a Swamp.

Bribery

Search target opponent's library for a creature card and put that card onto the battlefield under your control. Then that player shuffles.

Essence Flux

Exile target creature you control, then return that card to the battlefield under its owner's control. If it's a Spirit, put a +1/+1 counter on it.

Sunken Ruins

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Watery Grave

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

Agent of Treachery

When this creature enters, gain control of target permanent.
At the beginning of your end step, if you control three or more permanents you don't own, draw three cards.

Court of Vantress

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, choose up to one other target enchantment or artifact. If you're the monarch, you may create a token that's a copy of it. If you're not the monarch, you may have this enchantment become a copy of it, except it has this ability.

Staff of Eden, Vault's Key

When Staff of Eden enters, put target legendary permanent card not named Staff of Eden, Vault's Key from a graveyard onto the battlefield under your control.
{T}: Draw a card for each permanent you control but don't own.

The Darkness Crystal

Black spells you cast cost {1} less to cast.
If a nontoken creature an opponent controls would die, instead exile it and you gain 2 life.
{4}{B}{B}, {T}: Put target creature card exiled with The Darkness Crystal onto the battlefield tapped under your control with two additional +1/+1 counters on it.

Sol Ring

An Offer You Can't Refuse

Counter target noncreature spell. Its controller creates two Treasure tokens. (They're artifacts with "{T}, Sacrifice this token: Add one mana of any color.")

Dauthi Voidwalker

Shadow (This creature can block or be blocked by only creatures with shadow.)
If a card would be put into an opponent's graveyard from anywhere, instead exile it with a void counter on it.
{T}, Sacrifice this creature: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Arcane Signet

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

Deadly Rollick

If you control a commander, you may cast this spell without paying its mana cost.
Exile target creature.

Fealty to the Realm

Enchant creature
When this Aura enters, you become the monarch.
The monarch controls enchanted creature.
Enchanted creature attacks each combat if able and can't attack you.

Morphic Pool

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

Court of Locthwain

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, exile the top card of target opponent's library. You may play that card for as long as it remains exiled, and mana of any type can be spent to cast it. If you're the monarch, until end of turn, you may cast a spell from among cards exiled with this enchantment without paying its mana cost.

Conjurer's Closet

At the beginning of your end step, you may exile target creature you control, then return that card to the battlefield under your control.

Command Tower

Propaganda

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

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Swan Song

Counter target enchantment, instant, or sorcery spell. Its controller creates a 2/2 blue Bird creature token with flying.

Hostage Taker

When this creature enters, exile another target creature or artifact until this creature leaves the battlefield. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Fallen Shinobi

Ninjutsu {2}{U}{B} ({2}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, that player exiles the top two cards of their library. Until end of turn, you may play those cards without paying their mana costs.

Underground River

{T}: Add {C}.
{T}: Add {U} or {B}. This land deals 1 damage to you.

Come Back Wrong

Destroy target creature. If a creature card is put into a graveyard this way, return it to the battlefield under your control. Sacrifice it at the beginning of your next end step.

Aetherize

Return all attacking creatures to their owner's hand.

Treacherous Urge

Target opponent reveals their hand. You may put a creature card from it onto the battlefield under your control. That creature gains haste. Sacrifice it at the beginning of the next end step.

Drowned Catacomb

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

Lightning Greaves

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

Gonti, Lord of Luxury

Deathtouch
When Gonti enters, look at the top four cards of target opponent's library, exile one of them face down, then put the rest on the bottom of that library in a random order. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.

Court of Ambition

When this enchantment enters, you become the monarch.
At the beginning of your upkeep, each opponent loses 3 life unless they discard a card. If you're the monarch, instead each opponent loses 6 life unless they discard two cards.

Bojuka Bog

This land enters tapped.
When this land enters, exile target player's graveyard.
{T}: Add {B}.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Baleful Strix

Flying, deathtouch
When this creature enters, draw a card.

Dark Ritual

Garland, Royal Kidnapper

When Garland enters, target opponent becomes the monarch.
Whenever an opponent becomes the monarch, gain control of target creature that player controls for as long as they're the monarch.
Creatures you control but don't own get +2/+2 and can't be sacrificed.

Phyrexian Arena

At the beginning of your upkeep, you draw a card and you lose 1 life.

Shipwreck Marsh

This land enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Minion's Return

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

Urborg, Tomb of Yawgmoth

Each land is a Swamp in addition to its other land types.

Fellwar Stone

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

Ghostly Flicker

Exile two target artifacts, creatures, and/or lands you control, then return those cards to the battlefield under your control.

Thief of Sanity

Flying
Whenever this creature deals combat damage to a player, look at the top three cards of that player's library, exile one of them face down, then put the rest into their graveyard. You may cast that card for as long as it remains exiled, and mana of any type can be spent to cast that spell.