The One Ring

Indestructible
When The One Ring enters, if you cast it, you gain protection from everything until your next turn.
At the beginning of your upkeep, you lose 1 life for each burden counter on The One Ring.
{T}: Put a burden counter on The One Ring, then draw a card for each burden counter on The One Ring.

Ophiomancer

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Each player loses a third of their life, then discards a third of the cards in their hand, then sacrifices a third of the creatures they control of their choice, then sacrifices a third of the lands they control of their choice. Round up each time.

Wasteland

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

Winter Orb

As long as Winter Orb is untapped, players can't untap more than one land during their untap steps.

Gix, Yawgmoth Praetor

Whenever a creature deals combat damage to one of your opponents, its controller may pay 1 life. If they do, they draw a card.
{4}{B}{B}{B}, Discard X cards: Exile the top X cards of target opponent's library. You may play lands and cast spells from among cards exiled this way without paying their mana costs.

Bloodchief Ascension

At the beginning of each end step, if an opponent lost 2 or more life this turn, you may put a quest counter on Bloodchief Ascension. (Damage causes loss of life.)
Whenever a card is put into an opponent's graveyard from anywhere, if Bloodchief Ascension has three or more quest counters on it, you may have that player lose 2 life. If you do, you gain 2 life.

Dark Ritual

Arcane Signet

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

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Deadly Rollick

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

Storage Matrix

As long as Storage Matrix is untapped, each player chooses artifact, creature, or land during their untap step. That player can untap only permanents of the chosen type this step.

Dance of the Dead

Enchant creature card in a graveyard
When Dance of the Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Dance of the Dead." Put enchanted creature card onto the battlefield tapped under your control and attach Dance of the Dead to it. When Dance of the Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets +1/+1 and doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may pay {1}{B}. If the player does, untap that creature.

Francisco, Fowl Marauder

Flying
Francisco, Fowl Marauder can't block.
Whenever one or more Pirates you control deal damage to a player, Francisco explores.
Partner (You can have two commanders if both have partner.)

Entomb

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

Mikaeus, the Unhallowed

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)
Whenever a Human deals damage to you, destroy it.
Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)

Orb of Dreams

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Nether Void

Whenever a player casts a spell, counter it unless that player pays {3}.

Damping Sphere

If a land is tapped for two or more mana, it produces {C} instead of any other type and amount.
Each spell a player casts costs {1} more to cast for each other spell that player has cast this turn.

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Urza's Saga gains "{T}: Add {C}."
II — Urza's Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This creature gets +1/+1 for each artifact you control.'"
III — Search your library for an artifact card with mana cost {0} or {1}, put it onto the battlefield, then shuffle.

Torpor Orb

Creatures entering don't cause abilities to trigger.

Agatha's Soul Cauldron

You may spend mana as though it were mana of any color to activate abilities of creatures you control.
Creatures you control with +1/+1 counters on them have all activated abilities of all creature cards exiled with Agatha's Soul Cauldron.
{T}: Exile target card from a graveyard. When a creature card is exiled this way, put a +1/+1 counter on target creature you control.

Baleful Mastery

You may pay {1}{B} rather than pay this spell's mana cost.
If the {1}{B} cost was paid, an opponent draws a card.
Exile target creature or planeswalker.

Walking Ballista

Walking Ballista enters with X +1/+1 counters on it.
{4}: Put a +1/+1 counter on Walking Ballista.
Remove a +1/+1 counter from Walking Ballista: It deals 1 damage to any target.

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.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Chains of Mephistopheles

If a player would draw a card except the first one they draw in each of their draw steps, that player discards a card instead. If the player discards a card this way, they draw a card. If the player doesn't discard a card this way, they mill a card.

Peer into the Abyss

Target player draws cards equal to half the number of cards in their library and loses half their life. Round up each time.

Smokestack

At the beginning of your upkeep, you may put a soot counter on Smokestack.
At the beginning of each player's upkeep, that player sacrifices a permanent of their choice for each soot counter on Smokestack.

Great Unclean One

Reverberating Summons — At the beginning of your end step, each opponent loses 2 life. Then for each opponent who has less life than you, create a 1/3 black Demon creature token named Plaguebearer of Nurgle.

Imp's Mischief

Change the target of target spell with a single target. You lose life equal to that spell's mana value.

Static Orb

As long as Static Orb is untapped, players can't untap more than two permanents during their untap steps.

Bloodghast

Bloodghast can't block.
Bloodghast has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land you control enters, you may return Bloodghast from your graveyard to the battlefield.

Imperial Seal

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

Thorn of Amethyst

Noncreature spells cost {1} more to cast.

Cabal Coffers

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

Dark Deal

Each player discards all the cards in their hand, then draws that many cards minus one.

Sheoldred, the Apocalypse

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

Null Rod

Activated abilities of artifacts can't be activated.

Toxic Deluge

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

Chrome Mox

Imprint — When Chrome Mox enters, you may exile a nonartifact, nonland card from your hand.
{T}: Add one mana of any of the exiled card's colors.

Contamination

At the beginning of your upkeep, sacrifice Contamination unless you sacrifice a creature.
If a land is tapped for mana, it produces {B} instead of any other type and amount.

Sol Ring

Reanimate

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

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 Dauthi Voidwalker: Choose an exiled card an opponent owns with a void counter on it. You may play it this turn without paying its mana cost.

Mox Diamond

If Mox Diamond would enter, you may discard a land card instead. If you do, put Mox Diamond onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add one mana of any color.

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 of their choice that shares a card type with it. For each opponent who doesn't, that player loses 2 life and you draw a card.

Mana Web

Whenever a land an opponent controls is tapped for mana, tap all lands that player controls that could produce any type of mana that land could produce.

Triskelion

Triskelion enters with three +1/+1 counters on it.
Remove a +1/+1 counter from Triskelion: It deals 1 damage to any target.

Bitterblossom

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

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Mox Opal

Metalcraft — {T}: Add one mana of any color. Activate only if you control three or more artifacts.

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.

Yawgmoth's Will

Until end of turn, you may play lands and cast spells from your graveyard.
If a card would be put into your graveyard from anywhere this turn, exile that card instead.

Oppression

Whenever a player casts a spell, that player discards a card.

Necromancy

You may cast Necromancy as though it had flash. If you cast it any time a sorcery couldn't have been cast, the controller of the permanent it becomes sacrifices it at the beginning of the next cleanup step.
When Necromancy enters, if it's on the battlefield, it becomes an Aura with "enchant creature put onto the battlefield with Necromancy." Put target creature card from a graveyard onto the battlefield under your control and attach Necromancy to it. When Necromancy leaves the battlefield, that creature's controller sacrifices it.

Urborg, Tomb of Yawgmoth

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

Grim Tutor

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

Cabal Ritual

Add {B}{B}{B}.
Threshold — Add {B}{B}{B}{B}{B} instead if seven or more cards are in your graveyard.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Beseech the Mirror

Bargain (You may sacrifice an artifact, enchantment, or token as you cast this spell.)
Search your library for a card, exile it face down, then shuffle. If this spell was bargained, you may cast the exiled card without paying its mana cost if that spell's mana value is 4 or less. Put the exiled card into your hand if it wasn't cast this way.

Mana Crypt

At the beginning of your upkeep, flip a coin. If you lose the flip, Mana Crypt deals 3 damage to you.
{T}: Add {C}{C}.

Dismember

({B/P} can be paid with either {B} or 2 life.)
Target creature gets -5/-5 until end of turn.

Vampiric Tutor

Gemstone Caverns

If Gemstone Caverns is in your opening hand and you're not the starting player, you may begin the game with Gemstone Caverns on the battlefield with a luck counter on it. If you do, exile a card from your hand.
{T}: Add {C}. If Gemstone Caverns has a luck counter on it, instead add one mana of any color.

Swamp

Lake of the Dead

If Lake of the Dead would enter, sacrifice a Swamp instead. If you do, put Lake of the Dead onto the battlefield. If you don't, put it into its owner's graveyard.
{T}: Add {B}.
{T}, Sacrifice a Swamp: Add {B}{B}{B}{B}.

Wishclaw Talisman

This artifact enters with three wish counters on it.
{1}, {T}, Remove a wish counter from this artifact: Search your library for a card, put it into your hand, then shuffle. An opponent gains control of this artifact. Activate only during your turn.

Sphere of Resistance

Trinisphere

As long as Trinisphere is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost {1}{B} to cast costs {2}{B} to cast instead.)

Feed the Swarm

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

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

The Meathook Massacre

When The Meathook Massacre enters, each creature gets -X/-X until end of turn.
Whenever a creature you control dies, each opponent loses 1 life.
Whenever a creature an opponent controls dies, you gain 1 life.

Desolation

At the beginning of each end step, each player who tapped a land for mana this turn sacrifices a land of their choice. Desolation deals 2 damage to each player who sacrificed a Plains this way.

Bojuka Bog

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

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Strip Mine

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

Orcish Bowmasters

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

Tangle Wire

Fading 4 (This artifact enters with four fade counters on it. At the beginning of your upkeep, remove a fade counter from it. If you can't, sacrifice it.)
At the beginning of each player's upkeep, that player taps an untapped artifact, creature, or land they control for each fade counter on Tangle Wire.

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.