Tomb of Horrors Adventurer

When Tomb of Horrors Adventurer enters, you take the initiative.
Whenever you cast your second spell each turn, copy it. If you've completed a dungeon, copy that spell twice instead. You may choose new targets for the copies. (A copy of a permanent spell becomes a token.)

Bar the Gate

Counter target creature or planeswalker spell. Venture into the dungeon. (Enter the first room or advance to the next room.)

Seasoned Dungeoneer

When Seasoned Dungeoneer enters, you take the initiative.
Whenever you attack, target attacking Cleric, Rogue, Warrior, or Wizard gains protection from creatures until end of turn. It explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on the creature, then put the card back or put it into your graveyard.)

Azorius Signet

Secret Door

Defender
{4}{U}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Port Town

As Port Town enters, you may reveal a Plains or Island card from your hand. If you don't, Port Town enters tapped.
{T}: Add {W} or {U}.

Eccentric Apprentice

Flying
When Eccentric Apprentice enters, venture into the dungeon. (Enter the first room or advance to the next room.)
At the beginning of combat on your turn, if you've completed a dungeon, up to one target creature becomes a Bird with base power and toughness 1/1 and flying until end of turn.

Military Intelligence

Whenever you attack with two or more creatures, draw a card.

Hidden Courtyard

Hidden Courtyard enters tapped.
{T}: Add {W}.
{4}{W}, {T}, Sacrifice Hidden Courtyard: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Rowdy Research

This spell costs {1} less to cast for each creature that attacked this turn.
Draw three cards.

Cloister Gargoyle

When Cloister Gargoyle enters, venture into the dungeon. (Enter the first room or advance to the next room.)
As long as you've completed a dungeon, Cloister Gargoyle gets +3/+0 and has flying.

Celestial Crusader

Flash
Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Flying
Other white creatures get +1/+1.

Glacial Fortress

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

Trailblazer's Torch

When Trailblazer's Torch enters, you take the initiative.
Whenever equipped creature becomes blocked, it deals 2 damage to each creature blocking it.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Quick Study

Planar Ally

Flying
Whenever Planar Ally attacks, venture into the dungeon. (Enter the first room or advance to the next room.)

Otawara, Soaring City

{T}: Add {U}.
Channel — {3}{U}, Discard Otawara, Soaring City: 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.

Spear of Heliod

Creatures you control get +1/+1.
{1}{W}{W}, {T}: Destroy target creature that dealt damage to you this turn.

Restless Anchorage

Restless Anchorage enters tapped.
{T}: Add {W} or {U}.
{1}{W}{U}: Until end of turn, Restless Anchorage becomes a 2/3 white and blue Bird creature with flying. It's still a land.
Whenever Restless Anchorage attacks, create a Map token.

Immovable Rod

You may choose not to untap Immovable Rod during your untap step.
Whenever Immovable Rod becomes untapped, venture into the dungeon.
{3}{W}, {T}: For as long as Immovable Rod remains tapped, another target permanent loses all abilities and can't attack or block.

Paladin Class

(Gain the next level as a sorcery to add its ability.)
Spells your opponents cast during your turn cost {1} more to cast.
{2}{W}: Level 2
Creatures you control get +1/+1.
{4}{W}: Level 3
Whenever you attack, until end of turn, target attacking creature gets +1/+1 for each other attacking creature and gains double strike.

Island

Mirror Entity

Changeling (This card is every creature type.)
{X}: Until end of turn, creatures you control have base power and toughness X/X and gain all creature types.

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.

Gideon, Ally of Zendikar

+1: Until end of turn, Gideon, Ally of Zendikar becomes a 5/5 Human Soldier Ally creature with indestructible that's still a planeswalker. Prevent all damage that would be dealt to him this turn.
0: Create a 2/2 white Knight Ally creature token.
−4: You get an emblem with "Creatures you control get +1/+1."

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Always Watching

Nontoken creatures you control get +1/+1 and have vigilance.

Emeria, the Sky Ruin

Emeria, the Sky Ruin enters tapped.
At the beginning of your upkeep, if you control seven or more Plains, you may return target creature card from your graveyard to the battlefield.
{T}: Add {W}.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

Rogue's Passage

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

Sea of Clouds

Sea of Clouds enters tapped unless you have two or more opponents.
{T}: Add {W} or {U}.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

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.)

Hidden Cataract

Hidden Cataract enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice Hidden Cataract: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Goliath Paladin

Vigilance
When Goliath Paladin enters, you take the initiative.

Marshal's Anthem

Multikicker {1}{W} (You may pay an additional {1}{W} any number of times as you cast this spell.)
Creatures you control get +1/+1.
When Marshal's Anthem enters, return up to X target creature cards from your graveyard to the battlefield, where X is the number of times Marshal's Anthem was kicked.

Shortcut Seeker

Whenever Shortcut Seeker deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Intrepid Adversary

Lifelink
When Intrepid Adversary enters, you may pay {1}{W} any number of times. When you pay this cost one or more times, put that many valor counters on Intrepid Adversary.
Creatures you control get +1/+1 for each valor counter on Intrepid Adversary.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Veteran Dungeoneer

When Veteran Dungeoneer enters, venture into the dungeon. (Enter the first room or advance to the next room.)

Aarakocra Sneak

Flying
When Aarakocra Sneak enters, you take the initiative.

The Immortal Sun

Players can't activate planeswalkers' loyalty abilities.
At the beginning of your draw step, draw an additional card.
Spells you cast cost {1} less to cast.
Creatures you control get +1/+1.

Delver's Torch

Equipped creature gets +1/+1.
Whenever equipped creature attacks, venture into the dungeon. (Enter the first room or advance to the next room.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Yuan-Ti Malison

Yuan-Ti Malison can't be blocked as long as it's attacking alone.
Whenever Yuan-Ti Malison deals combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Lavaspur Boots

Equipped creature gets +1/+0 and has haste and ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {1}

Dungeon Delver

Commander creatures you own have "Room abilities of dungeons you own trigger an additional time."

Feywild Caretaker

When Feywild Caretaker enters, you take the initiative.
At the beginning of your end step, if you have the initiative, create a 1/1 blue Faerie Dragon creature token with flying.

Ultramarines Honour Guard

Squad {2} (As an additional cost to cast this spell, you may pay {2} any number of times. When this creature enters, create that many tokens that are copies of it.)
Other creatures you control get +1/+1.

White Plume Adventurer

When White Plume Adventurer enters, you take the initiative.
At the beginning of each opponent's upkeep, untap a creature you control. If you've completed a dungeon, untap all creatures you control instead.

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Command Tower

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

Trouble in Pairs

If an opponent would begin an extra turn, that player skips that turn instead.
Whenever an opponent attacks you with two or more creatures, draws their second card each turn, or casts their second spell each turn, you draw a card.

Ranger's Hawk

Flying
{3}, {T}, Tap another untapped creature you control: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Radiant Solar

Flying, lifelink
Whenever Radiant Solar or another nontoken creature you control enters, venture into the dungeon. (Enter the first room or advance to the next room.)
{W}, Discard Radiant Solar: Venture into the dungeon and you gain 3 life.

Sol Ring

Dictate of Heliod

Deserted Beach

Deserted Beach enters tapped unless you control two or more other lands.
{T}: Add {W} or {U}.

Overflowing Insight

Hama Pashar, Ruin Seeker

Room abilities of dungeons you own trigger an additional time.

Ponder

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

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.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Dungeon Descent

Dungeon Descent enters tapped.
{T}: Add {C}.
{4}, {T}, Tap an untapped legendary creature you control: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Arcane Signet

Hallowed Fountain

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

Undercellar Sweep

When Undercellar Sweep enters, you take the initiative.
Whenever you attack, if you or a player you're attacking has the initiative, you create two 1/1 white Soldier creature tokens that are tapped and attacking.

Glorious Anthem

Dungeon Map

{T}: Add {C}.
{3}, {T}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Plains

Imoen, Mystic Trickster

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
At the beginning of your end step, if you have the initiative, draw a card. Draw another card if you've completed a dungeon.
Choose a Background (You can have a Background as a second commander.)

Force of Virtue

If it's not your turn, you may exile a white card from your hand rather than pay this spell's mana cost.
Flash
Creatures you control get +1/+1.

Fifty Feet of Rope

Climb Over — {T}: Target Wall can't block this turn.
Tie Up — {3}, {T}: Target creature doesn't untap during its controller's next untap step.
Rappel Down — {4}, {T}: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Dungeoneer's Pack

Dungeoneer's Pack enters tapped.
{2}, {T}, Sacrifice Dungeoneer's Pack: You take the initiative, gain 3 life, draw a card, and create a Treasure token. Activate only as a sorcery. (A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Midnight Pathlighter

Creatures you control can't be blocked except by legendary creatures.
Whenever one or more creatures you control deal combat damage to a player, venture into the dungeon. (Enter the first room or advance to the next room.)

Thorough Investigation

Whenever you attack, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, venture into the dungeon. (Enter the first room or advance to the next room.)

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Horn of the Mark

Whenever two or more creatures you control attack a player, look at the top five cards of your library. You may reveal a creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

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."

Levitation

Nadaar, Selfless Paladin

Vigilance
Whenever Nadaar, Selfless Paladin enters or attacks, venture into the dungeon. (Enter the first room or advance to the next room.)
Other creatures you control get +1/+1 as long as you've completed a dungeon.

Sarevok's Tome

When Sarevok's Tome enters, you take the initiative.
{T}: Add {C}. If you have the initiative, add {C}{C} instead.
{3}, {T}: Exile cards from the top of your library until you exile a nonland card. You may cast that card without paying its mana cost. Activate only if you've completed a dungeon.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Enchant creature
Enchanted creature has flying and "Whenever this creature deals combat damage to a player, venture into the dungeon." (Enter the first room or advance to the next room.)

Mind Stone

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

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Displacer Beast

When Displacer Beast enters, venture into the dungeon. (Enter the first room or advance to the next room.)
Displacement — {3}{U}: Return Displacer Beast to its owner's hand.

Impulse

Look at the top four cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Disorder in the Court

Exile X target creatures, then investigate X times. Return the exiled cards to the battlefield tapped under their owners' control at the beginning of the next end step. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")