Demonic Tutor

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

Consider

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

Baleful Strix

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

Inundated Archive

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

Waterlogged Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.

Waterlogged Teachings // Inundated Archive

Bruvac the Grandiloquent

If an opponent would mill one or more cards, they mill twice that many cards instead. (To mill a card, a player puts the top card of their library into their graveyard.)

Hullbreaker Horror

Flash
This spell can't be countered.
Whenever you cast a spell, choose up to one —
• Return target spell you don't control to its owner's hand.
• Return target nonland permanent to its owner's hand.

Valley Floodcaller

Flash
You may cast noncreature spells as though they had flash.
Whenever you cast a noncreature spell, Birds, Frogs, Otters, and Rats you control get +1/+1 until end of turn. Untap them.

Frantic Search

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

Gale, Waterdeep Prodigy

Whenever you cast an instant or sorcery spell from your hand, you may cast up to one target card of the other type from your graveyard. If a spell cast from your graveyard this way would be put into your graveyard, exile it instead.
Choose a Background (You can have a Background as a second commander.)

Duskmantle Guildmage

{1}{U}{B}: Whenever a card is put into an opponent's graveyard from anywhere this turn, that player loses 1 life.
{2}{U}{B}: Target player mills two cards.

Stitch Together

Return target creature card from your graveyard to your hand.
Threshold — Return that card from your graveyard to the battlefield instead if seven or more cards are in your graveyard.

Archmage of Runes

Instant and sorcery spells you cast cost {1} less to cast.
Whenever you cast an instant or sorcery spell, draw a card.

Retraced Image

Reveal a card in your hand, then put that card onto the battlefield if it has the same name as a permanent.

Mystical Tutor

Search your library for an instant or sorcery card, reveal it, then shuffle and put that card on top.

Serum Visions

Bojuka Bog

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

Torrential Gearhulk

Flash
When this creature enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Emergence Zone

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

Entomb

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

Command Tower

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

Force of Will

You may pay 1 life and exile a blue card from your hand rather than pay this spell's mana cost.
Counter target spell.

Silundi Isle

Silundi Vision

Look at the top six cards of your library. You may reveal an instant or sorcery card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Silundi Vision // Silundi Isle

Dig Through Time

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Look at the top seven cards of your library. Put two of them into your hand and the rest on the bottom of your library in any order.

Flare of Denial

You may sacrifice a nontoken blue creature rather than pay this spell's mana cost.
Counter target spell.

Watery Grave

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

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.

Hydroelectric Laboratory

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

Hydroelectric Specimen

Flash
When this creature enters, you may change the target of target instant or sorcery spell with a single target to this creature.

Hydroelectric Specimen // Hydroelectric Laboratory

Rhystic Study

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

Urza's Saga

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — This Saga gains "{T}: Add {C}."
II — This Saga gains "{2}, {T}: Create a 0/0 colorless Construct artifact creature token with 'This token 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.

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.

Deadly Rollick

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

Snuff Out

If you control a Swamp, you may pay 4 life rather than pay this spell's mana cost.
Destroy target nonblack creature. It can't be regenerated.

Feed the Swarm

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

High Fae Trickster

Flash (You may cast this spell any time you could cast an instant.)
Flying
You may cast spells as though they had flash.

Undercity Sewers

({T}: Add {U} or {B}.)
This land enters tapped.
When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Faerie Mastermind

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

Snapcaster Mage

Flash
When this creature enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Arcane Signet

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}.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

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.

Mindcrank

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

Wizards of Thay

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Instant and sorcery spells you cast cost {1} less to cast.
You may cast sorcery spells as though they had flash.

Counterspell

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.

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Gemstone Caverns

If this card 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.

Cabal Ritual

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

Borne Upon a Wind

You may cast spells this turn as though they had flash.
Draw a card.

Dark Ritual

Chrome Mox

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

Gifts Ungiven

Search your library for up to four cards with different names and reveal them. Target opponent chooses two of those cards. Put the chosen cards into your graveyard and the rest into your hand. Then shuffle.

Withering Torment

Destroy target creature or enchantment. You lose 2 life.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Temporal Cleansing

Convoke (Your creatures can help cast this spell. Each creature you tap while casting this spell pays for {1} or one mana of that creature's color.)
The owner of target nonland permanent puts it into their library second from the top or on the bottom.

Propaganda

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

Swamp

Soporific Springs

Sink into Stupor

Return target spell or nonland permanent an opponent controls to its owner's hand.

Sink into Stupor // Soporific Springs

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

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

Mystic Sanctuary

({T}: Add {U}.)
This land enters tapped unless you control three or more other Islands.
When this land enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Sol Ring

Snap

Return target creature to its owner's hand. Untap up to two lands.

Prismatic Vista

{T}, Pay 1 life, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield, then shuffle.

See Double

This spell can't be copied.
Choose one. If an opponent has eight or more cards in their graveyard, you may choose both instead.
• Copy target spell. You may choose new targets for the copy. (A copy of a permanent spell becomes a token.)
• Create a token that's a copy of target creature.

Guildless Commons

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {C}{C}.

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard this card: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs {1} less to activate for each legendary creature you control.

Sunken Hollow

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

Ghost Vacuum

{T}: Exile target card from a graveyard.
{6}, {T}, Sacrifice this artifact: Put each creature card exiled with this artifact onto the battlefield under your control with a flying counter on it. Each of them is a 1/1 Spirit in addition to its other types. Activate only as a sorcery.

Reanimate

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

Drowned Catacomb

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

Maddening Cacophony

Kicker {3}{U}
Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Ledger Shredder

Flying
Whenever a player casts their second spell each turn, this creature connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Scion of Halaster

Commander creatures you own have "The first time you would draw a card each turn, instead look at the top two cards of your library. Put one of them into your graveyard and the other back on top of your library. Then draw a card."

Polluted Delta

{T}, Pay 1 life, Sacrifice this land: Search your library for an Island or Swamp card, put it onto the battlefield, then shuffle.

Baral's Expertise

Return up to three target artifacts and/or creatures to their owners' hands.
You may cast a spell with mana value 4 or less from your hand without paying its mana cost.

Archmage Emeritus

Magecraft — Whenever you cast or copy an instant or sorcery spell, draw a card.

Island

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.