Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters the battlefield, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Rogue's Passage

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

Mithril Coat

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

Ezio Auditore da Firenze

Menace
Assassin spells you cast have freerunning {B}{B}. (You may cast a spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)
Whenever Ezio deals combat damage to a player, you may pay {W}{U}{B}{R}{G} if that player has 10 or less life. When you do, that player loses the game.

Isolated Chapel

Isolated Chapel enters the battlefield tapped unless you control a Plains or a Swamp.
{T}: Add {W} or {B}.

Silver Shroud Costume

Flash
When Silver Shroud Costume enters the battlefield, attach it to target creature you control. That creature gains shroud until end of turn. (It can't be the target of spells or abilities.)
Equipped creature can't be blocked.
Equip {3}

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Timeless Lotus

Timeless Lotus enters the battlefield tapped.
{T}: Add {W}{U}{B}{R}{G}.

Sandsteppe Citadel

Sandsteppe Citadel enters the battlefield tapped.
{T}: Add {W}, {B}, or {G}.

Propaganda

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

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Rootbound Crag

Rootbound Crag enters the battlefield tapped unless you control a Mountain or a Forest.
{T}: Add {R} or {G}.

Mindbreak Trap

If an opponent cast three or more spells this turn, you may pay {0} rather than pay this spell's mana cost.
Exile any number of target spells.

Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Realmwalker

Changeling (This card is every creature type.)
As Realmwalker enters the battlefield, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.

Virtus the Veiled

Partner with Gorm the Great (When this creature enters the battlefield, target player may put Gorm into their hand from their library, then shuffle.)
Deathtouch
Whenever Virtus the Veiled deals combat damage to a player, that player loses half their life, rounded up.

Sulfur Falls

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

Savage Lands

Savage Lands enters the battlefield tapped.
{T}: Add {B}, {R}, or {G}.

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

The World Tree

The World Tree enters the battlefield tapped.
{T}: Add {G}.
As long as you control six or more lands, lands you control have "{T}: Add one mana of any color."
{W}{W}{U}{U}{B}{B}{R}{R}{G}{G}, {T}, Sacrifice The World Tree: Search your library for any number of God cards, put them onto the battlefield, then shuffle.

Command Tower

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

Adaptive Automaton

As Adaptive Automaton enters the battlefield, choose a creature type.
Adaptive Automaton is the chosen type in addition to its other types.
Other creatures you control of the chosen type get +1/+1.

Unsettled Mariner

Changeling (This card is every creature type.)
Whenever you or a permanent you control becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {1}.

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Rogue Class

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control deals combat damage to a player, exile the top card of that player's library face down. You may look at it for as long as it remains exiled.
{1}{U}{B}: Level 2
Creatures you control have menace.
{2}{U}{B}: Level 3
You may play cards exiled with Rogue Class, and you may spend mana as though it were mana of any color to cast those spells.

Frontier Bivouac

Frontier Bivouac enters the battlefield tapped.
{T}: Add {G}, {U}, or {R}.

Forest

Island

Raise the Palisade

Choose a creature type. Return all creatures that aren't of the chosen type to their owners' hands.

Roaming Throne

Ward {2}
As Roaming Throne enters the battlefield, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Door of Destinies

As Door of Destinies enters the battlefield, choose a creature type.
Whenever you cast a spell of the chosen type, put a charge counter on Door of Destinies.
Creatures you control of the chosen type get +1/+1 for each charge counter on Door of Destinies.

Cover of Darkness

As Cover of Darkness enters the battlefield, choose a creature type.
Creatures of the chosen type have fear. (They can't be blocked except by artifact creatures and/or black creatures.)

Demonic Tutor

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

Basilisk Collar

Equipped creature has deathtouch and lifelink.
Equip {2}

Opulent Palace

Opulent Palace enters the battlefield tapped.
{T}: Add {B}, {G}, or {U}.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Quietus Spike

Equipped creature has deathtouch.
Whenever equipped creature deals combat damage to a player, that player loses half their life, rounded up.
Equip {3}

Spellbook

Dragonskull Summit

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

Drowned Catacomb

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

Kelsien, the Plague

Vigilance, haste
Kelsien, the Plague gets +1/+1 for each experience counter you have.
{T}: Kelsien deals 1 damage to target creature you don't control. When that creature dies this turn, you get an experience counter.

Mari, the Killing Quill

Whenever a creature an opponent controls dies, exile it with a hit counter on it.
Assassins, Mercenaries, and Rogues you control have deathtouch and "Whenever this creature deals combat damage to a player, you may remove a hit counter from a card that player owns in exile. If you do, draw a card and create two Treasure tokens."

Urza's Incubator

As Urza's Incubator enters the battlefield, choose a creature type.
Creature spells of the chosen type cost {2} less to cast.

Hinterland Harbor

Hinterland Harbor enters the battlefield tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Sorin Markov

+2: Sorin Markov deals 2 damage to any target and you gain 2 life.
−3: Target opponent's life total becomes 10.
−7: You control target player during that player's next turn.

Reliquary Tower

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

Ramses, Assassin Lord

Deathtouch
Other Assassins you control get +1/+1.
Whenever a player loses the game, if they were attacked this turn by an Assassin you controlled, you win the game.

Rhythm of the Wild

Creature spells you control can't be countered.
Nontoken creatures you control have riot. (They enter the battlefield with your choice of a +1/+1 counter or haste.)

Shizo, Death's Storehouse

{T}: Add {B}.
{B}, {T}: Target legendary creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Assassin

Decanter of Endless Water

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

Plains

Seaside Citadel

Seaside Citadel enters the battlefield tapped.
{T}: Add {G}, {W}, or {U}.

Arcane Signet

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Diabolic Tutor

Sol Ring

Massacre Girl, Known Killer

Menace
Creatures you control have wither. (They deal damage to creatures in the form of -1/-1 counters.)
Whenever a creature an opponent controls dies, if its toughness was less than 1, draw a card.

Woodland Cemetery

Woodland Cemetery enters the battlefield tapped unless you control a Swamp or a Forest.
{T}: Add {B} or {G}.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Nomad Outpost

Nomad Outpost enters the battlefield tapped.
{T}: Add {R}, {W}, or {B}.

Chromatic Orrery

You may spend mana as though it were mana of any color.
{T}: Add {C}{C}{C}{C}{C}.
{5}, {T}: Draw a card for each color among permanents you control.

Queen Marchesa

Deathtouch, haste
When Queen Marchesa enters the battlefield, you become the monarch.
At the beginning of your upkeep, if an opponent is the monarch, create a 1/1 black Assassin creature token with deathtouch and haste.

Negate

Black Market

Whenever a creature dies, put a charge counter on Black Market.
At the beginning of your precombat main phase, add {B} for each charge counter on Black Market.

Arcane Sanctum

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

Cavern of Souls

As Cavern of Souls enters the battlefield, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Glacial Fortress

Glacial Fortress enters the battlefield tapped unless you control a Plains or an Island.
{T}: Add {W} or {U}.

Ochran Assassin

Deathtouch
All creatures able to block Ochran Assassin do so.

Vein Ripper

Flying
Ward—Sacrifice a creature.
Whenever a creature dies, target opponent loses 2 life and you gain 2 life.

Rising of the Day

Creatures you control have haste.
Legendary creatures you control get +1/+0.

Tree of Perdition

Defender
{T}: Exchange target opponent's life total with Tree of Perdition's toughness.

Thraximundar

Haste
Whenever Thraximundar attacks, defending player sacrifices a creature.
Whenever a player sacrifices a creature, you may put a +1/+1 counter on Thraximundar.

Swamp

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Haystack

{2}, {T}: Target creature you control phases out.

Sunpetal Grove

Sunpetal Grove enters the battlefield tapped unless you control a Forest or a Plains.
{T}: Add {G} or {W}.

Shadowspear

Equipped creature gets +1/+1 and has trample and lifelink.
{1}: Permanents your opponents control lose hexproof and indestructible until end of turn.
Equip {2}

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Mystic Monastery

Mystic Monastery enters the battlefield tapped.
{T}: Add {U}, {R}, or {W}.

Crumbling Necropolis

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

Crippling Fear

Choose a creature type. Creatures that aren't of the chosen type get -3/-3 until end of turn.

Kindred Dominance

Choose a creature type. Destroy all creatures that aren't of the chosen type.

Counterspell

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Grand Abolisher

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.

Coerced to Kill

Enchant creature
You control enchanted creature.
Enchanted creature has base power and toughness 1/1, has deathtouch, and is an Assassin in addition to its other types.

Ghostly Prison

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.

Jungle Shrine

Jungle Shrine enters the battlefield tapped.
{T}: Add {R}, {G}, or {W}.

Mountain

Fierce Guardianship

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