Darksteel Myr

Indestructible (Damage and effects that say "destroy" don't destroy this creature. If its toughness is 0 or less, it's still put into its owner's graveyard.)

Tocasia's Dig Site

{T}: Add {C}.
{3}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Changeling Outcast

Changeling (This card is every creature type.)
This creature can't block and can't be blocked.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.

Phage the Untouchable

When Phage enters, if you didn't cast it from your hand, you lose the game.
Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated.
Whenever Phage deals combat damage to a player, that player loses the game.

The Core

(Transforms from Matzalantli.)
Fathomless descent — {T}: Add X mana of any one color, where X is the number of permanent cards in your graveyard.

Matzalantli, the Great Door

{T}: Draw a card, then discard a card.
{4}, {T}: Transform Matzalantli. Activate only if there are four or more permanent types among cards in your graveyard. (Artifact, battle, creature, enchantment, land, and planeswalker are permanent types.)

Matzalantli, the Great Door // The Core

Leveler

When this creature enters, exile all cards from your library.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever this artifact becomes untapped, you may pay {2}. If you do, draw a card.

Sword of Once and Future

Equipped creature gets +2/+2 and has protection from blue and from black.
Whenever equipped creature deals combat damage to a player, surveil 2. Then you may cast an instant or sorcery spell with mana value 2 or less from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.
Equip {2}

Arcane Signet

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

Counterspell

Sol Ring

Wharf Infiltrator

Skulk (This creature can't be blocked by creatures with greater power.)
Whenever this creature deals combat damage to a player, you may draw a card. If you do, discard a card.
Whenever you discard a creature card, you may pay {2}. If you do, create a 3/2 colorless Eldrazi Horror creature token.

Worn Powerstone

This artifact enters tapped.
{T}: Add {C}{C}.

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Likeness Looter

Flying
{T}: Draw a card, then discard a card.
{X}: This creature becomes a copy of target creature card in your graveyard with mana value X, except it has flying and this ability. Activate only as a sorcery.

Dark Ritual

Necrotic Ooze

As long as this creature is on the battlefield, it has all activated abilities of all creature cards in all graveyards.

Perpetual Timepiece

{T}: Mill two cards.
{2}, Exile this artifact: Shuffle any number of target cards from your graveyard into your library.

Sleep-Cursed Faerie

Flying, ward {2}
This creature enters tapped with three stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
{1}{U}: Untap this creature.

Feed the Swarm

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

Ringsight

The Ring tempts you. Search your library for a card that shares a color with a legendary creature you control, reveal it, put it into your hand, then shuffle.

Cavern Harpy

Flying
When this creature enters, return a blue or black creature you control to its owner's hand.
Pay 1 life: Return this creature to its owner's hand.

Unmarked Grave

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

Dimir Infiltrator

This creature can't be blocked.
Transmute {1}{U}{B} ({1}{U}{B}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Reenact the Crime

Exile target nonland card in a graveyard that was put there from anywhere this turn. Copy it. You may cast the copy without paying its mana cost.

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Ghostly Pilferer

Whenever this creature becomes untapped, you may pay {2}. If you do, draw a card.
Whenever an opponent casts a spell from anywhere other than their hand, draw a card.
Discard a card: This creature can't be blocked this turn.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Dimir Signet

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Consider

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

Academy Ruins

{T}: Add {C}.
{1}{U}, {T}: Put target artifact card from your graveyard on top of your library.

Faerie Mastermind

Flash
Flying
Whenever an opponent draws their second card each turn, you draw a card.
{3}{U}: Each player draws a card.

Negate

The Ancient One

Descend 8 — The Ancient One can't attack or block unless there are eight or more permanent cards in your graveyard.
{2}{U}{B}: Draw a card, then discard a card. When you discard a card this way, target player mills cards equal to its mana value.

Vohar, Vodalian Desecrator

{T}: Draw a card, then discard a card. If you discarded an instant or sorcery card this way, each opponent loses 1 life and you gain 1 life.
{2}, Sacrifice Vohar: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead. Activate only as a sorcery.

Reliquary Tower

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

Price of Fame

This spell costs {2} less to cast if it targets a legendary creature.
Destroy target creature.
Surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice this artifact: Draw a card.

Can't Wake Up

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

Cruel Somnophage

Cruel Somnophage's power and toughness are each equal to the number of creature cards in all graveyards.

Cruel Somnophage // Can't Wake Up

Fellwar Stone

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

Island

Thought Scour

Target player mills two cards.
Draw a card.

Baleful Strix

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

Locus of Enlightenment

Locus of Enlightenment has each activated ability of the exiled cards used to craft it. You may activate each of those abilities only once each turn.
Whenever you activate an ability that isn't a mana ability, copy it. You may choose new targets for the copy.

The Enigma Jewel

The Enigma Jewel enters tapped.
{T}: Add {C}{C}. Spend this mana only to activate abilities.
Craft with four or more nonlands with activated abilities {8}{U} ({8}{U}, Exile this artifact, Exile the four or more from among other permanents you control and/or cards in your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

The Enigma Jewel // Locus of Enlightenment

Enhanced Surveillance

You may look at an additional two cards each time you surveil.
Exile this enchantment: Shuffle your graveyard into your library.

Rhystic Study

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

Merfolk Looter

Rona, Tolarian Obliterator

Trample
Whenever a source deals damage to Rona, that source's controller exiles a card from their hand at random. If it's a land card, you may put it onto the battlefield under your control. Otherwise, you may cast it without paying its mana cost.

Rona, Herald of Invasion

Whenever you cast a legendary spell, untap Rona.
{T}: Draw a card, then discard a card.
{5}{B/P}: Transform Rona. Activate only as a sorcery. ({B/P} can be paid with either {B} or 2 life.)

Rona, Herald of Invasion // Rona, Tolarian Obliterator

The Grim Captain's Locker

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Until end of turn, each creature card in your graveyard gains "Escape—{3}{B}, Exile four other cards from your graveyard." (You may cast a card with escape from your graveyard for its escape cost.)

The Myriad Pools

(Transforms from The Everflowing Well.)
{T}: Add {U}.
Whenever you cast a permanent spell using mana produced by The Myriad Pools, up to one other target permanent you control becomes a copy of that spell until end of turn.

The Everflowing Well

When The Everflowing Well enters, mill two cards, then draw two cards.
Descend 8 — At the beginning of your upkeep, if there are eight or more permanent cards in your graveyard, transform The Everflowing Well.

The Everflowing Well // The Myriad Pools

Thran Dynamo

Compulsive Research

Target player draws three cards. Then that player discards two cards unless they discard a land card.

Mist-Cloaked Herald

Disinformation Campaign

When this enchantment enters, you draw a card and each opponent discards a card.
Whenever you surveil, return this enchantment to its owner's hand.

Final Parting

Search your library for two cards. Put one into your hand and the other into your graveyard. Then shuffle.

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Criminal Past

Commander creatures you own have menace and "This creature gets +X/+0, where X is the number of creature cards in your graveyard." (A creature with menace can't be blocked except by two or more creatures.)

Eater of Days

Flying, trample
When this creature enters, you skip your next two turns.

Consuming Aberration

Consuming Aberration's power and toughness are each equal to the number of cards in your opponents' graveyards.
Whenever you cast a spell, each opponent reveals cards from the top of their library until they reveal a land card, then puts those cards into their graveyard.

Lazav, the Multifarious

When Lazav enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{X}: Lazav becomes a copy of target creature card in your graveyard with mana value X, except its name is Lazav, the Multifarious, it's legendary in addition to its other types, and it has this ability.

Swamp

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Talisman of Dominance

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

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Nighthowler

Bestow {2}{B}{B} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
This creature and enchanted creature each get +X/+X, where X is the number of creature cards in all graveyards.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
This artifact enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on this artifact.

Laboratory Maniac

If you would draw a card while your library has no cards in it, you win the game instead.

Nightveil Sprite

Flying
Whenever this creature attacks, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Command Tower

Mirror-Mad Phantasm

Flying
{1}{U}: This creature's owner shuffles it into their library. If that player does, they reveal cards from the top of that library until a card named Mirror-Mad Phantasm is revealed. The player puts that card onto the battlefield and all other cards revealed this way into their graveyard.

Looter il-Kor

Shadow (This creature can block or be blocked by only creatures with shadow.)
Whenever this creature deals damage to an opponent, draw a card, then discard a card.