Wall of Junk

Defender (This creature can't attack.)
When Wall of Junk blocks, return it to its owner's hand at end of combat. (Return it only if it's on the battlefield.)

Thryx, the Sudden Storm

Flash (You may cast this spell any time you could cast an instant.)
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Divine Reckoning

Each player chooses a creature they control. Destroy the rest.
Flashback {5}{W}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Forceful Denial

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Counter target spell.

The Initiative

Whenever one or more creatures a player controls deal combat damage to you, that player takes the initiative.
Whenever you take the initiative and at the beginning of your upkeep, venture into Undercity. (If you're in a dungeon, advance to the next room. If you're not, enter Undercity. You can take the initiative even if you already have it.)

Have

Undercity

You can't enter this dungeon unless you "venture into Undercity."
Secret Entrance — Search your library for a basic land card, reveal it, put it into your hand, then shuffle. (Leads to: Forge, Lost Well)
Forge — Put two +1/+1 counters on target creature. (Leads to: Trap!, Arena)
Lost Well — Scry 2. (Leads to: Arena, Stash)
Trap! — Target player loses 5 life. (Leads to: Archives)
Arena — Goad target creature. (Leads to: Archives, Catacombs)
Stash — Create a Treasure token. (Leads to: Catacombs)
Archives — Draw a card. (Leads to: Throne of the Dead Three)
Catacombs — Create a 4/1 black Skeleton creature token with menace. (Leads to: Throne of the Dead Three)
Throne of the Dead Three — Reveal the top ten cards of your library. Put a creature card from among them onto the battlefield with three +1/+1 counters on it. It gains hexproof until your next turn. Then shuffle.

Undercity // The Initiative

Jace's Sanctum

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

Shipwreck Marsh

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

Press the Enemy

Return target spell or nonland permanent an opponent controls to its owner's hand. You may cast an instant or sorcery spell with equal or lesser mana value from your hand without paying its mana cost.

Voidmage Husher

Flash (You may cast this spell any time you could cast an instant.)
When Voidmage Husher enters, counter target activated ability. (Mana abilities can't be targeted.)
Whenever you cast a spell, you may return Voidmage Husher to its owner's hand.

Lobelia Sackville-Baggins

Flash
Menace
When Lobelia Sackville-Baggins enters, exile target creature card from an opponent's graveyard that was put there from the battlefield this turn, then create X Treasure tokens, where X is the exiled card's power.

Sea Gate

Sea Gate enters tapped.
As Sea Gate enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Dromar, the Banisher

Flying
Whenever Dromar, the Banisher deals combat damage to a player, you may pay {2}{U}. If you do, choose a color, then return all creatures of that color to their owners' hands.

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.

Sculpted Sunburst

Choose a creature you control, then each opponent chooses a creature they control with equal or lesser power. If you chose a creature this way, exile each creature not chosen by any player this way.

Idyllic Beachfront

({T}: Add {W} or {U}.)
Idyllic Beachfront enters tapped.

Arcane Sanctum

Arcane Sanctum enters tapped.
{T}: Add {W}, {U}, or {B}.

Tranquil Cove

Tranquil Cove enters tapped.
When Tranquil Cove enters, you gain 1 life.
{T}: Add {W} or {U}.

Crafty Cutpurse

Flash
When Crafty Cutpurse enters, each token that would be created under an opponent's control this turn is created under your control instead.

Asinine Antics

You may cast Asinine Antics as though it had flash if you pay {2} more to cast it.
For each creature your opponents control, create a Cursed Role token attached to that creature. (If you control another Role on it, put that one into the graveyard. Enchanted creature is 1/1.)

Decanter of Endless Water

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

Orzhov Basilica

Orzhov Basilica enters tapped.
When Orzhov Basilica enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

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.

Arcane Proxy

Prototype {1}{U}{U} — 2/1 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
When Arcane Proxy enters, if you cast it, exile target instant or sorcery card with mana value less than or equal to Arcane Proxy's power from your graveyard. Copy that card. You may cast the copy without paying its mana cost.

Doomskar Oracle

Whenever you cast your second spell each turn, you gain 2 life.
Foretell {W} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Archaeomancer's Map

When Archaeomancer's Map enters, search your library for up to two basic Plains cards, reveal them, put them into your hand, then shuffle.
Whenever a land an opponent controls enters, if that player controls more lands than you, you may put a land card from your hand onto the battlefield.

Epistolary Librarian

Veil of Time — Whenever Epistolary Librarian attacks, you may cast a spell with mana value X or less from your hand without paying its mana cost, where X is the number of attacking creatures.

Hauken's Insight

At the beginning of your upkeep, exile the top card of your library face down. You may look at that card for as long as it remains exiled.
Once during each of your turns, you may play a land or cast a spell from among the cards exiled with this permanent without paying its mana cost.

Jacob Hauken, Inspector

{T}: Draw a card, then exile a card from your hand face down. You may look at that card for as long as it remains exiled. You may pay {4}{U}{U}. If you do, transform Jacob Hauken, Inspector.

Jacob Hauken, Inspector // Hauken's Insight

Flux Channeler

Whenever you cast a noncreature spell, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Wondrous Crucible

Permanents you control have ward {2}.
At the beginning of your end step, mill two cards, then exile a nonland card at random from your graveyard. Copy it. You may cast the copy without paying its mana cost. (A copy of a permanent spell becomes a token.)

Cemetery Illuminator

Flying
Whenever Cemetery Illuminator enters or attacks, exile a card from a graveyard.
You may look at the top card of your library any time.
Once each turn, you may cast a spell from the top of your library if it shares a card type with a card exiled with Cemetery Illuminator.

Geyser Drake

Flying
During turns other than yours, spells you cast cost {1} less to cast.

Liesa, Forgotten Archangel

Flying, lifelink
Whenever another nontoken creature you control dies, return that card to its owner's hand at the beginning of the next end step.
If a creature an opponent controls would die, exile it instead.

Gloomlake Verge

{T}: Add {U}.
{T}: Add {B}. Activate only if you control an Island or a Swamp.

Blinking Spirit

{0}: Return Blinking Spirit to its owner's hand.

Exotic Orchard

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

Sphinx of the Final Word

This spell can't be countered.
Flying, hexproof
Instant and sorcery spells you control can't be countered.

Glamdring

Equipped creature has first strike and gets +1/+0 for each instant and sorcery card in your graveyard.
Whenever equipped creature deals combat damage to a player, you may cast an instant or sorcery spell from your hand with mana value less than or equal to that damage without paying its mana cost.
Equip {3}

Sloppity Bilepiper

Jolly Gutpipes — {2}, {T}, Sacrifice a creature: The next creature spell you cast this turn has cascade. (When you next cast a creature spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

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.

Sram's Expertise

Create three 1/1 colorless Servo artifact creature tokens.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Yahenni's Expertise

All creatures get -3/-3 until end of turn.
You may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Azorius Signet

The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Go for the Throat

Saruman of Many Colors

Ward—Discard an enchantment, instant, or sorcery card.
Whenever you cast your second spell each turn, each opponent mills two cards. When one or more cards are milled this way, exile target enchantment, instant, or sorcery card with equal or lesser mana value than that spell from an opponent's graveyard. Copy the exiled card. You may cast the copy without paying its mana cost.

Lotho, Corrupt Shirriff

Whenever a player casts their second spell each turn, you lose 1 life and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Barrin, Tolarian Archmage

When Barrin, Tolarian Archmage enters, return up to one other target creature or planeswalker to its owner's hand.
At the beginning of your end step, if a permanent was put into your hand from the battlefield this turn, draw a card.

Ratadrabik of Urborg

Vigilance, ward {2}
Other Zombies you control have vigilance.
Whenever another legendary creature you control dies, create a token that's a copy of that creature, except it's not legendary and it's a 2/2 black Zombie in addition to its other colors and types.

Black Dragon Gate

Black Dragon Gate enters tapped.
As Black Dragon Gate enters, choose a color other than black.
{T}: Add {B} or one mana of the chosen color.

Memory Plunder

You may cast target instant or sorcery card from an opponent's graveyard without paying its mana cost.

Contaminated Landscape

{T}: Add {C}.
{T}, Sacrifice Contaminated Landscape: Search your library for a basic Plains, Island, or Swamp card, put it onto the battlefield tapped, then shuffle.
Cycling {W}{U}{B} ({W}{U}{B}, Discard this card: Draw a card.)

Deny Reality

Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)
Return target permanent to its owner's hand.

Defiler of Faith

Vigilance
As an additional cost to cast white permanent spells, you may pay 2 life. Those spells cost {W} less to cast if you paid life this way. This effect reduces only the amount of white mana you pay.
Whenever you cast a white permanent spell, create a 1/1 white Soldier creature token.

Plains

Soundwave, Superior Captain

Whenever you cast a spell with an odd mana value, convert Soundwave. If you do, create Ravage, a legendary 3/3 black Robot artifact creature token with menace and deathtouch.
Whenever you cast a spell with an even mana value, convert Soundwave. If you do, create Laserbeak, a legendary 2/2 blue Robot artifact creature token with flying and hexproof.

Soundwave, Sonic Spy

More Than Meets the Eye {2}{W}{U}{B} (You may cast this card converted for {2}{W}{U}{B}.)
Whenever one or more creature tokens you control deal combat damage to a player, exile target instant or sorcery card with mana value equal to the damage dealt from their graveyard. Copy it. You may cast the copy without paying its mana cost. If you do, convert Soundwave.

Soundwave, Sonic Spy // Soundwave, Superior Captain

Urza, Lord Protector

Artifact, instant, and sorcery spells you cast cost {1} less to cast.
{7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Command Tower

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

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.

Kaya the Inexorable

+1: Put a ghostform counter on up to one target nontoken creature. It gains "When this creature dies or is put into exile, return it to its owner's hand and create a 1/1 white Spirit creature token with flying."
−3: Exile target nonland permanent.
−7: You get an emblem with "At the beginning of your upkeep, you may cast a legendary spell from your hand, from your graveyard, or from among cards you own in exile without paying its mana cost."

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Monk Class

(Gain the next level as a sorcery to add its ability.)
The second spell you cast each turn costs {1} less to cast.
{W}{U}: Level 2
When this Class becomes level 2, return up to one target nonland permanent to its owner's hand.
{1}{W}{U}: Level 3
At the beginning of your upkeep, exile the top card of your library. For as long as it remains exiled, it has "You may cast this card from exile as long as you've cast another spell this turn."

Mass Diminish

Until your next turn, creatures target player controls have base power and toughness 1/1.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Archmage Emeritus

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

Choked Estuary

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

Twinning Staff

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.
{7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

God-Eternal Kefnet

Flying
You may reveal the first card you draw each turn as you draw it. Whenever you reveal an instant or sorcery card this way, copy that card and you may cast the copy. That copy costs {2} less to cast.
When God-Eternal Kefnet dies or is put into exile from the battlefield, you may put it into its owner's library third from the top.

Heliod, the Warped Eclipse

You may cast spells as though they had flash.
Spells you cast cost {1} less to cast for each card your opponents have drawn this turn.

Heliod, the Radiant Dawn

When Heliod, the Radiant Dawn enters, return target enchantment card that isn't a God from your graveyard to your hand.
{3}{U/P}: Transform Heliod, the Radiant Dawn. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.)

Heliod, the Radiant Dawn // Heliod, the Warped Eclipse

Crabomination

Emerge from artifact {5}{B}{B} (You may cast this spell by sacrificing an artifact and paying the emerge cost reduced by that artifact's mana value.)
When Crabomination enters, target opponent exiles the top card of their library, a card at random from their graveyard, and a card at random from their hand. You may cast a spell from among cards exiled this way without paying its mana cost.

Scholar of the Lost Trove

Flying
When Scholar of the Lost Trove enters, you may cast target instant, sorcery, or artifact card from your graveyard without paying its mana cost. If an instant or sorcery spell cast this way would be put into your graveyard, exile it instead.

Treasure

{T}, Sacrifice this artifact: Add one mana of any color.

Samwise the Stouthearted

Flash
When Samwise the Stouthearted enters, choose up to one target permanent card in your graveyard that was put there from the battlefield this turn. Return it to your hand. Then the Ring tempts you.

Shambling Vent

Shambling Vent enters tapped.
{T}: Add {W} or {B}.
{1}{W}{B}: Shambling Vent becomes a 2/3 white and black Elemental creature with lifelink until end of turn. It's still a land.

Ethersworn Sphinx

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
Cascade (When you cast this spell, exile cards from the top of your library until you exile a nonland card with lesser mana value. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order.)

The Council of Four

Whenever a player draws their second card during their turn, you draw a card.
Whenever a player casts their second spell during their turn, you create a 2/2 white Knight creature token.

Psionic Ritual

Replicate—Tap an untapped Horror you control. (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Exile target instant or sorcery card from a graveyard and copy it. You may cast the copy without paying its mana cost.
Exile Psionic Ritual.

Gossamer Chains

Return Gossamer Chains to its owner's hand: Prevent all combat damage that would be dealt by target unblocked creature this turn.

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Path of Ancestry

Path of Ancestry 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.)

Voracious Fell Beast

Flying
When Voracious Fell Beast enters, each opponent sacrifices a creature of their choice. Create a Food token for each creature sacrificed this way. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Subjugate the Hobbits

Gain control of each noncommander creature with mana value 3 or less.

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Boromir, Warden of the Tower

Vigilance
Whenever an opponent casts a spell, if no mana was spent to cast it, counter that spell.
Sacrifice Boromir, Warden of the Tower: Creatures you control gain indestructible until end of turn. The Ring tempts you.

As Foretold

At the beginning of your upkeep, put a time counter on As Foretold.
Once each turn, you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less, where X is the number of time counters on As Foretold.

Sphinx of the Steel Wind

Flying, first strike, vigilance, lifelink, protection from red and from green

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Ancestral Statue

When Ancestral Statue enters, return a nonland permanent you control to its owner's hand.

Food

{2}, {T}, Sacrifice this artifact: You gain 3 life.

Fabricate

Search your library for an artifact card, reveal it, put it into your hand, then shuffle.

Unesh, Criosphinx Sovereign

Flying
Sphinx spells you cast cost {2} less to cast.
Whenever Unesh, Criosphinx Sovereign or another Sphinx you control enters, reveal the top four cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Semblance Anvil

Imprint — When Semblance Anvil enters, you may exile a nonland card from your hand.
Spells you cast that share a card type with the exiled card cost {2} less to cast.

Flawless Forgery

Casualty 3 (As you cast this spell, you may sacrifice a creature with power 3 or greater. When you do, copy this spell and you may choose a new target for the copy.)
Exile target instant or sorcery card from an opponent's graveyard. Copy that card. You may cast the copy without paying its mana cost.

Defiler of Flesh

Menace
As an additional cost to cast black permanent spells, you may pay 2 life. Those spells cost {B} less to cast if you paid life this way. This effect reduces only the amount of black mana you pay.
Whenever you cast a black permanent spell, target creature you control gets +1/+1 and gains menace until end of turn.

Yawgmoth's Vile Offering

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Put up to one target creature or planeswalker card from a graveyard onto the battlefield under your control. Destroy up to one target creature or planeswalker. Exile Yawgmoth's Vile Offering.

Pearl Medallion

White spells you cast cost {1} less to cast.

Gollum, Patient Plotter

When Gollum, Patient Plotter leaves the battlefield, the Ring tempts you.
{B}, Sacrifice a creature: Return Gollum from your graveyard to your hand. Activate only as a sorcery.

Mithril Coat

Flash
Indestructible
When Mithril Coat enters, attach it to target legendary creature you control.
Equipped creature has indestructible.
Equip {3}