Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Morphic Pool

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

Defenestrate

Drowned Catacomb

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

Consuming Corruption

Consuming Corruption deals X damage to target creature or planeswalker and you gain X life, where X is the number of Swamps you control.

Counterspell

Eliminate

Destroy target creature or planeswalker with mana value 3 or less.

Fellwar Stone

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

Shipwreck Marsh

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

Island

Swamp

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.")

Swan Song

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

Mindslaver

{4}, {T}, Sacrifice Mindslaver: You control target player during that player's next turn. (You see all cards that player could see and make all decisions for the player.)

Sunken Hollow

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

Commandeer

You may exile two blue cards from your hand rather than pay this spell's mana cost.
Gain control of target noncreature spell. You may choose new targets for it. (If that spell is an artifact, enchantment, or planeswalker, the permanent enters under your control.)

Butcher of Malakir

Flying
Whenever this creature or another creature you control dies, each opponent sacrifices a creature of their choice.

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.")

Cabal Stronghold

{T}: Add {C}.
{3}, {T}: Add {B} for each basic Swamp you control.

Altar of Dementia

Sacrifice a creature: Target player mills cards equal to the sacrificed creature's power.

Urborg, Tomb of Yawgmoth

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

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

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.

Dimir Signet

Praetor's Grasp

Search target opponent's library for a card and exile it face down. Then that player shuffles. You may play that card for as long as it remains exiled.

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Sephiroth, One-Winged Angel

Flying
Super Nova — As this creature transforms into Sephiroth, One-Winged Angel, you get an emblem with "Whenever a creature dies, target opponent loses 1 life and you gain 1 life."
Whenever Sephiroth attacks, you may sacrifice any number of other creatures. If you do, draw that many cards.

Sephiroth, Fabled SOLDIER

Whenever Sephiroth enters or attacks, you may sacrifice another creature. If you do, draw a card.
Whenever another creature dies, target opponent loses 1 life and you gain 1 life. If this is the fourth time this ability has resolved this turn, transform Sephiroth.

Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel

Emrakul, the Promised End

This spell costs {1} less to cast for each card type among cards in your graveyard.
When you cast this spell, you gain control of target opponent during that player's next turn. After that turn, that player takes an extra turn.
Flying, trample, protection from instants

Talisman of Dominance

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

Evolving Wilds

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

Command Tower

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

Nightmare Incursion

Search target player's library for up to X cards, where X is the number of Swamps you control, and exile them. Then that player shuffles.

Opposition Agent

Flash
You control your opponents while they're searching their libraries.
While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Bitter Ordeal

Search target player's library for a card and exile it. Then that player shuffles.
Gravestorm (When you cast this spell, copy it for each permanent put into a graveyard this turn. You may choose new targets for the copies.)

Fleshbag Marauder

When this creature enters, each player sacrifices a creature of their choice.

Arcane Signet

Rev, Tithe Extractor

Whenever you attack, target creature gains deathtouch until end of turn.
Whenever one or more creatures you control deal combat damage to a player, create a Treasure token, then look at the top card of that player's library and exile it face down. You may cast that card for as long as it remains exiled. (A Treasure token is an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Deadly Rollick

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

Overkill

Target creature gets -0/-9999 until end of turn.

Ashnod's Altar

Alela, Cunning Conqueror

Flying
Whenever you cast your first spell during each opponent's turn, create a 1/1 black Faerie Rogue creature token with flying.
Whenever one or more Faeries you control deal combat damage to a player, goad target creature that player controls.

Dictate of Erebos

Flash
Whenever a creature you control dies, each opponent sacrifices a creature of their choice.

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.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Decanter of Endless Water

You have no maximum hand size.
{T}: Add one mana of any color.

City of Brass

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Sothera, the Supervoid

Whenever a creature you control dies, each opponent chooses a creature they control and exiles it.
At the beginning of your end step, if a player controls no creatures, sacrifice Sothera, then put a creature card exiled with it onto the battlefield under your control with two additional +1/+1 counters on it.

Thought Vessel

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

Terramorphic Expanse

Cabal Coffers

{2}, {T}: Add {B} for each Swamp you control.

Underground River

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

Fell Mire

As this land enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {B}.

Fell the Profane

Fell the Profane // Fell Mire

Strip Mine

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

Orcish Bowmasters

Flash
When this creature enters and whenever an opponent draws a card except the first one they draw in each of their draw steps, this creature deals 1 damage to any target. Then amass Orcs 1.

Go for the Throat

Spell Stutter

Counter target spell unless its controller pays {2} plus an additional {1} for each Faerie you control.

Force of Despair

If it's not your turn, you may exile a black card from your hand rather than pay this spell's mana cost.
Destroy all creatures that entered this turn.

Sol Ring

Feed the Swarm

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

Phyrexian Altar

Sacrifice a creature: Add one mana of any color.

Blue Sun's Twilight

Gain control of target creature with mana value X or less. If X is 5 or more, create a token that's a copy of that creature.

Murder

Jester's Cap

{2}, {T}, Sacrifice this artifact: Search target player's library for three cards and exile them. Then that player shuffles.

Force of Negation

If it's not your turn, you may exile a blue card from your hand rather than pay this spell's mana cost.
Counter target noncreature spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Bitter Triumph

As an additional cost to cast this spell, discard a card or pay 3 life.
Destroy target creature or planeswalker.

Confiscation Coup

Choose target artifact or creature. You get {E}{E}{E}{E} (four energy counters), then you may pay an amount of {E} equal to that permanent's mana value. If you do, gain control of it.

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.

Beguiler of Wills

{T}: Gain control of target creature with power less than or equal to the number of creatures you control.

Scheming Symmetry

Choose two target players. Each of them searches their library for a card, then shuffles and puts that card on top.

Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

Blatant Thievery

For each opponent, gain control of target permanent that player controls.

Thoughtseize

Target player reveals their hand. You choose a nonland card from it. That player discards that card. You lose 2 life.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Roil Elemental

Flying
Landfall — Whenever a land you control enters, you may gain control of target creature for as long as you control this creature.

Brainsurge

Draw four cards, then put two cards from your hand on top of your library in any order.

Grave Pact

Whenever a creature you control dies, each other player sacrifices a creature of their choice.