Nekusar, the Mindrazer

At the beginning of each player's draw step, that player draws an additional card.
Whenever an opponent draws a card, Nekusar deals 1 damage to that player.

Bountiful Promenade

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

Decree of Pain

Destroy all creatures. They can't be regenerated. Draw a card for each creature destroyed this way.
Cycling {3}{B}{B} ({3}{B}{B}, Discard this card: Draw a card.)
When you cycle this card, all creatures get -2/-2 until end of turn.

Anvil of Bogardan

Players have no maximum hand size.
At the beginning of each player's draw step, that player draws an additional card, then discards a card.

Demonic Tutor

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

Badlands

Tropical Island

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Shipwreck Marsh

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

Millstone

Keeper of the Accord

At the beginning of each opponent's end step, if that player controls more creatures than you, create a 1/1 white Soldier creature token.
At the beginning of each opponent's end step, if that player controls more lands than you, you may search your library for a basic Plains card, put it onto the battlefield tapped, then shuffle.

Underground Sea

Luxury Suite

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

Viseling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is the number of cards in their hand minus 4.

Sundown Pass

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

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Arcane Signet

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

Price of Knowledge

Players have no maximum hand size.
At the beginning of each opponent's upkeep, this enchantment deals damage to that player equal to the number of cards in that player's hand.

Ms. Bumbleflower

Vigilance
Whenever you cast a spell, target opponent draws a card. Put a +1/+1 counter on target creature. It gains flying until end of turn. If this is the second time this ability has resolved this turn, you draw two cards.

Crumbling Necropolis

This land enters tapped.
{T}: Add {U}, {B}, or {R}.

Sea of Clouds

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

Deathcap Glade

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

Mystic Remora

Cumulative upkeep {1} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Whenever an opponent casts a noncreature spell, you may draw a card unless that player pays {4}.

Psychic Corrosion

Whenever you draw a card, each opponent mills two cards.

Arcane Sanctum

This land enters tapped.
{T}: Add {W}, {U}, or {B}.

Bayou

Plateau

Mind Twist

Target player discards X cards at random.

Ob Nixilis of the Black Oath

+2: Each opponent loses 1 life. You gain life equal to the life lost this way.
−2: Create a 5/5 black Demon creature token with flying. You lose 2 life.
−8: You get an emblem with "{1}{B}, Sacrifice a creature: You gain X life and draw X cards, where X is the sacrificed creature's power."
Ob Nixilis of the Black Oath can be your commander.

Consecrated Sphinx

Flying
Whenever an opponent draws a card, you may draw two cards.

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Training Center

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

Grindstone

{3}, {T}: Target player mills two cards. If two cards that share a color were milled this way, repeat this process.

Sign in Blood

Target player draws two cards and loses 2 life.

Bojuka Bog

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

Spire Garden

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

Shattered Sanctum

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

Taiga

Ruinous Ultimatum

Destroy all nonland permanents your opponents control.

Gruul Signet

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Szadek, Lord of Secrets

Flying
If Szadek would deal combat damage to a player, instead put that many +1/+1 counters on Szadek and that player mills that many cards.

Child of Alara

Trample
When Child of Alara dies, destroy all nonland permanents. They can't be regenerated.

Rackling

At the beginning of each opponent's upkeep, this creature deals X damage to that player, where X is 3 minus the number of cards in their hand.

Nomad Outpost

This land enters tapped.
{T}: Add {R}, {W}, or {B}.

Propaganda

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

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Rockfall Vale

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

The Water Crystal

Blue spells you cast cost {1} less to cast.
If an opponent would mill one or more cards, they mill that many cards plus four instead.
{4}{U}{U}, {T}: Each opponent mills cards equal to the number of cards in your hand.

Exotic Orchard

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

Howling Mine

At the beginning of each player's draw step, if this artifact is untapped, that player draws an additional card.

Sol Ring

Mundungu

{T}: Counter target spell unless its controller pays {1} and 1 life.

Haunted Ridge

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

Simic Ascendancy

{1}{G}{U}: Put a +1/+1 counter on target creature you control.
Whenever one or more +1/+1 counters are put on a creature you control, put that many growth counters on this enchantment.
At the beginning of your upkeep, if this enchantment has twenty or more growth counters on it, you win the game.

Stormcarved Coast

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

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet deals 1 damage to any target.
{T}: Draw a card.

Morphic Pool

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

Undergrowth Stadium

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

Jungle Hollow

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {B} or {G}.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Jace Beleren

+2: Each player draws a card.
−1: Target player draws a card.
−10: Target player mills twenty cards.

Vault of Champions

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

Raiders' Wake

Whenever an opponent discards a card, that player loses 2 life.
Raid — At the beginning of your end step, if you attacked this turn, target opponent discards a card.

Damnation

Destroy all creatures. They can't be regenerated.

Izzet Signet

Rejuvenating Springs

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

Abundance

If you would draw a card, you may instead choose land or nonland and reveal cards from the top of your library until you reveal a card of the chosen kind. Put that card into your hand and put all other cards revealed this way on the bottom of your library in any order.

Ivory Tower

At the beginning of your upkeep, you gain X life, where X is the number of cards in your hand minus 4.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is this creature's power.

Sylvan Library

At the beginning of your draw step, you may draw two additional cards. If you do, choose two cards in your hand drawn this turn. For each of those cards, pay 4 life or put the card on top of your library.

Wedding Ring

When this artifact enters, if it was cast, target opponent creates a token that's a copy of it.
Whenever an opponent who controls an artifact named Wedding Ring draws a card during their turn, you draw a card.
Whenever an opponent who controls an artifact named Wedding Ring gains life during their turn, you gain that much life.

Torment of Hailfire

Repeat the following process X times. Each opponent loses 3 life unless that player sacrifices a nonland permanent of their choice or discards a card.

Command Tower

Spectator Seating

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

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Maze of Ith

{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.

Vodalian Mage

{U}, {T}: Counter target spell unless its controller pays {1}.

Sheoldred, the Apocalypse

Deathtouch
Whenever you draw a card, you gain 2 life.
Whenever an opponent draws a card, they lose 2 life.

Underworld Dreams

Whenever an opponent draws a card, this enchantment deals 1 damage to that player.

Kiora's Follower

Diabolic Tutor

Bottomless Pit

At the beginning of each player's upkeep, that player discards a card at random.

Narset, Parter of Veils

Each opponent can't draw more than one card each turn.
−2: Look at the top four cards of your library. You may reveal a noncreature, nonland card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Megrim

Whenever an opponent discards a card, this enchantment deals 2 damage to that player.

Soldevi Digger

{2}: Put the top card of your graveyard on the bottom of your library.

Exquisite Blood

Whenever an opponent loses life, you gain that much life.

Indatha Triome

({T}: Add {W}, {B}, or {G}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Braingeyser

Scrubland

Elemental Augury

{3}: Look at the top three cards of target player's library, then put them back in any order.

Nine-Tail White Fox

Whenever this creature deals combat damage to a player, draw a card.

Volcanic Island

Opulent Palace

This land enters tapped.
{T}: Add {B}, {G}, or {U}.

Fate Unraveler

Whenever an opponent draws a card, this creature deals 1 damage to that player.

Savannah

Tundra

Dimir Signet

Ketria Triome

({T}: Add {G}, {U}, or {R}.)
This land enters tapped.
Cycling {3} ({3}, Discard this card: Draw a card.)

Ensnaring Bridge

Creatures with power greater than the number of cards in your hand can't attack.