Epic Experiment

Exile the top X cards of your library. You may cast instant and sorcery spells with mana value X or less from among them without paying their mana costs. Then put all cards exiled this way that weren't cast into your graveyard.

Geothermal Bog

({T}: Add {B} or {R}.)
Geothermal Bog enters the battlefield tapped.

Infernal Grasp

Destroy target creature. You lose 2 life.

Canyon Slough

({T}: Add {B} or {R}.)
Canyon Slough enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Mountain

Thought Vessel

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

Sol Ring

Fetid Pools

({T}: Add {U} or {B}.)
Fetid Pools enters the battlefield tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Tainted Isle

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

Niv-Mizzet, the Firemind

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

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, Vodalian Desecrator: 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.

Nightscape Familiar

Blue spells and red spells you cast cost {1} less to cast.
{1}{B}: Regenerate Nightscape Familiar.

Scrabbling Claws

{T}: Target player exiles a card from their graveyard.
{1}, Sacrifice Scrabbling Claws: Exile target card from a graveyard. Draw a card.

Izzet Signet

Arcane Bombardment

Whenever you cast your first instant or sorcery spell each turn, exile an instant or sorcery card at random from your graveyard. Then copy each card exiled with Arcane Bombardment. You may cast any number of the copies without paying their mana costs.

Mindsplice Apparatus

Flash
At the beginning of your upkeep, put an oil counter on Mindsplice Apparatus.
Instant and sorcery spells you cast cost {1} less to cast for each oil counter on Mindsplice Apparatus.

Sulfurous Mire

({T}: Add {B} or {R}.)
Sulfurous Mire enters the battlefield tapped.

Ovika, Enigma Goliath

Flying
Ward—{3}, Pay 3 life.
Whenever you cast a noncreature spell, create X 1/1 red Phyrexian Goblin creature tokens, where X is the mana value of that spell. They gain haste until end of turn.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Ice Tunnel

({T}: Add {U} or {B}.)
Ice Tunnel enters the battlefield tapped.

Victimize

Choose two target creature cards in your graveyard. Sacrifice a creature. If you do, return the chosen cards to the battlefield tapped.

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.

Counterspell

Gut Shot

({R/P} can be paid with either {R} or 2 life.)
Gut Shot deals 1 damage to any target.

Dragonskull Summit

Dragonskull Summit enters the battlefield tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Tainted Peak

{T}: Add {C}.
{T}: Add {B} or {R}. Activate only if you control a Swamp.

Zombify

Return target creature card from your graveyard to the battlefield.

Take the Fall

Target creature gets -1/-0 until end of turn. It gets -4/-0 until end of turn instead if you control an outlaw. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)
Draw a card.

Gitaxian Probe

({U/P} can be paid with either {U} or 2 life.)
Look at target player's hand.
Draw a card.

Arcane Signet

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

Underworld Breach

Each nonland card in your graveyard has escape. The escape cost is equal to the card's mana cost plus exile three other cards from your graveyard. (You may cast cards from your graveyard for their escape cost.)
At the beginning of the end step, sacrifice Underworld Breach.

Dimir Signet

Swarm Intelligence

Whenever you cast an instant or sorcery spell, you may copy that spell. You may choose new targets for the copy.

Fellwar Stone

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

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters the battlefield tapped.

Thousand-Year Storm

Whenever you cast an instant or sorcery spell, copy it for each other instant and sorcery spell you've cast before it this turn. You may choose new targets for the copies.

Ertai's Scorn

This spell costs {U} less to cast if an opponent cast two or more spells this turn.
Counter target spell.

Reliquary Tower

Go for the Throat

Painful Truths

Converge — You draw X cards and you lose X life, where X is the number of colors of mana spent to cast this spell.

Contaminated Aquifer

({T}: Add {U} or {B}.)
Contaminated Aquifer enters the battlefield tapped.

Seething Song

Drown in the Loch

Choose one —
• Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.
• Destroy target creature with mana value less than or equal to the number of cards in its controller's graveyard.

Strike It Rich

Create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.)

Sulfur Falls

Sulfur Falls enters the battlefield tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

Thought Scour

Target player mills two cards.
Draw a card.

Archmage's Newt

Whenever Archmage's Newt deals combat damage to a player, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. That card gains flashback {0} until end of turn instead if Archmage's Newt is saddled. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
Saddle 3

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Tor Wauki the Younger

Reach, lifelink
If another source you control would deal noncombat damage to a permanent or player, it deals that much damage plus 1 to that permanent or player instead.
Whenever you cast an instant or sorcery spell, Tor Wauki the Younger deals 2 damage to any target.

Fleeting Distraction

Target creature gets -1/-0 until end of turn.
Draw a card.

Mizzix's Mastery

Exile target card that's an instant or sorcery from your graveyard. For each card exiled this way, copy it, and you may cast the copy without paying its mana cost. Exile Mizzix's Mastery.
Overload {5}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters the battlefield tapped.

Dark Ritual

Rakdos Charm

Choose one —
• Exile target player's graveyard.
• Destroy target artifact.
• Each creature deals 1 damage to its controller.

Drowned Catacomb

Drowned Catacomb enters the battlefield tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Foreboding Ruins

As Foreboding Ruins enters the battlefield, you may reveal a Swamp or Mountain card from your hand. If you don't, Foreboding Ruins enters the battlefield tapped.
{T}: Add {B} or {R}.

Wizards of Thay

Myriad (Whenever this creature attacks, for each opponent other than defending player, you may create a token that's a copy of this creature 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.

Command Tower

The Great Work

(As this Saga enters and after your draw step, add a lore counter.)
I — The Great Work deals 3 damage to target opponent and each creature they control.
II — Create three Treasure tokens.
III — Until end of turn, you may cast instant and sorcery spells from any graveyard. If a spell cast this way would be put into a graveyard, exile it instead. Exile The Great Work, then return it to the battlefield (front face up).

Urabrask

First strike
Whenever you cast an instant or sorcery spell, Urabrask deals 1 damage to target opponent. Add {R}.
{R}: Exile Urabrask, then return it to the battlefield transformed under its owner's control. Activate only as a sorcery and only if you've cast three or more instant and/or sorcery spells this turn.

Urabrask // The Great Work

Voracious Reader

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Instant and sorcery spells you cast cost {1} less to cast.

Curious Homunculus

{T}: Add {C}. Spend this mana only to cast an instant or sorcery spell.
At the beginning of your upkeep, if there are three or more instant and/or sorcery cards in your graveyard, transform Curious Homunculus.

Curious Homunculus // Voracious Reader

Swamp

Feed the Swarm

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

Solphim, Mayhem Dominus

If a source you control would deal noncombat damage to an opponent or a permanent an opponent controls, it deals double that damage to that player or permanent instead.
{1}{R/P}{R/P}, Discard two cards: Put an indestructible counter on Solphim, Mayhem Dominus. ({R/P} can be paid with either {R} or 2 life.)

Crumbling Necropolis

Crumbling Necropolis enters the battlefield tapped.
{T}: Add {U}, {B}, or {R}.

Cormela, Glamour Thief

Haste
{1}, {T}: Add {U}{B}{R}. Spend this mana only to cast instant and/or sorcery spells.
When Cormela, Glamour Thief dies, return up to one target instant or sorcery card from your graveyard to your hand.

Marchesa, Dealer of Death

Whenever you commit a crime, you may pay {1}. If you do, look at the top two cards of your library. Put one of them into your hand and the other into your graveyard. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Choked Estuary

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

Frostboil Snarl

As Frostboil Snarl enters the battlefield, you may reveal an Island or Mountain card from your hand. If you don't, Frostboil Snarl enters the battlefield tapped.
{T}: Add {U} or {R}.

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.

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Rodeo Pyromancers

Whenever you cast your first spell each turn, add {R}{R}.

Smoldering Marsh

({T}: Add {B} or {R}.)
Smoldering Marsh enters the battlefield tapped unless you control two or more basic lands.

Path of Ancestry

Path of Ancestry enters the battlefield 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.)

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Goblin Electromancer

Instant and sorcery spells you cast cost {1} less to cast.

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.

Peek

Look at target player's hand.
Draw a card.

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Exotic Orchard

Dance with Calamity

Shuffle your library. As many times as you choose, you may exile the top card of your library. If the total mana value of the cards exiled this way is 13 or less, you may cast any number of spells from among those cards without paying their mana costs.

Rakdos Signet

Glasses of Urza

Treasure Cruise

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

Tendrils of Agony

Target player loses 2 life and you gain 2 life.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Island

Resculpt

Exile target artifact or creature. Its controller creates a 4/4 blue and red Elemental creature token.