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.)

Dispersal Shield

Counter target spell if its mana value is less than or equal to the highest mana value among permanents you control.

Windreader Sphinx

Flying
Whenever a creature with flying attacks, you may draw a card.

Thraben Watcher

Flying, vigilance
Other nontoken creatures you control get +1/+1 and have vigilance.

Merfolk Thaumaturgist

{T}: Switch target creature's power and toughness until end of turn.

Karn, Silver Golem

Whenever Karn, Silver Golem blocks or becomes blocked, it gets -4/+4 until end of turn.
{1}: Target noncreature artifact becomes an artifact creature with power and toughness each equal to its mana value until end of turn.

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.)

Snow Fortress

Defender (This creature can't attack.)
{1}: Snow Fortress gets +1/+0 until end of turn.
{1}: Snow Fortress gets +0/+1 until end of turn.
{3}: Snow Fortress deals 1 damage to target creature without flying that's attacking you.

Glacial Fortress

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

Fell the Mighty

Destroy all creatures with power greater than target creature's power.

Disruption Protocol

As an additional cost to cast this spell, tap an untapped artifact you control or pay {1}.
Counter target spell.

Kry Shield

{2}, {T}: Prevent all damage that would be dealt this turn by target creature you control. That creature gets +0/+X until end of turn, where X is its mana value.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Familiar's Ruse

As an additional cost to cast this spell, return a creature you control to its owner's hand.
Counter target spell.

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Solidarity

Creatures you control get +0/+5 until end of turn.

Dovin's Veto

This spell can't be countered.
Counter target noncreature spell.

Odric, Lunarch Marshal

At the beginning of each combat, creatures you control gain first strike until end of turn if a creature you control has first strike. The same is true for flying, deathtouch, double strike, haste, hexproof, indestructible, lifelink, menace, reach, skulk, trample, and vigilance.

Holy Armor

Enchant creature
Enchanted creature gets +0/+2.
{W}: Enchanted creature gets +0/+1 until end of turn.

Hover Barrier

Mask of Memory

Whenever equipped creature deals combat damage to a player, you may draw two cards. If you do, discard a card.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Sky Diamond

Trenching Steed

Sacrifice a land: Trenching Steed gets +0/+3 until end of turn.

Charix, the Raging Isle

Spells your opponents cast that target Charix, the Raging Isle cost {2} more to cast.
{3}: Charix gets +X/-X until end of turn, where X is the number of Islands you control.

Narset's Reversal

Copy target instant or sorcery spell, then return it to its owner's hand. You may choose new targets for the copy.

Marble Gargoyle

Flying
{W}: Marble Gargoyle gets +0/+1 until end of turn.

Staggering Insight

Enchant creature
Enchanted creature gets +1/+1 and has lifelink and "Whenever this creature deals combat damage to a player, draw a card."

Goliath Paladin

Vigilance
When Goliath Paladin enters, you take the initiative.

Spectral Deluge

Return each creature your opponents control with toughness X or less to its owner's hand, where X is the number of Islands you control.
Foretell {1}{U}{U} (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.)

Crenellated Wall

Defender (This creature can't attack.)
{T}: Target creature gets +0/+4 until end of turn.

Secret Rendezvous

You and target opponent each draw three cards.

Steadfast Armasaur

Vigilance
{1}{W}, {T}: Steadfast Armasaur deals damage equal to its toughness to target creature blocking or blocked by it.

Stoneskin

Flash
Enchant creature
Enchanted creature gets +0/+10.

Tide Drifter

Devoid (This card has no color.)
Other colorless creatures you control get +0/+1.

Cephalid Facetaker

Cephalid Facetaker can't be blocked.
At the beginning of combat on your turn, you may have Cephalid Facetaker become a copy of another target creature until end of turn, except it's 1/4 and has "This creature can't be blocked."

Ith, High Arcanist

Vigilance
{T}: Untap target attacking creature. Prevent all combat damage that would be dealt to and dealt by that creature this turn.
Suspend 4—{W}{U}

Mystic Gate

{T}: Add {C}.
{W/U}, {T}: Add {W}{W}, {W}{U}, or {U}{U}.

Everflowing Chalice

Multikicker {2} (You may pay an additional {2} any number of times as you cast this spell.)
Everflowing Chalice enters with a charge counter on it for each time it was kicked.
{T}: Add {C} for each charge counter on Everflowing Chalice.

Tireless Tribe

Discard a card: Tireless Tribe gets +0/+4 until end of turn.

Access Tunnel

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

Robe of Stars

Equipped creature gets +0/+3.
Astral Projection — {1}{W}: Equipped creature phases out. (Treat it and anything attached to it as though they don't exist until its controller's next turn.)
Equip {1}

Hindering Light

Counter target spell that targets you or a permanent you control.
Draw a card.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Counterspell

Belbe's Armor

{X}, {T}: Target creature gets -X/+X until end of turn.

Gift of Granite

Flash (You may cast this spell any time you could cast an instant.)
Enchant creature
Enchanted creature gets +0/+2.

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}.

Combat Research

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
As long as enchanted creature is legendary, it gets +1/+1 and has ward {1}. (Whenever enchanted creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Engulf the Shore

Return to their owners' hands all creatures with toughness less than or equal to the number of Islands you control.

Cathar's Shield

Equipped creature gets +0/+3 and has vigilance.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Castle

Untapped creatures you control get +0/+2.

Hard Cover

Enchant creature
Enchanted creature gets +0/+2 and has "{T}: Draw a card, then discard a card."

Sea of Clouds

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

Leering Gargoyle

Flying
{T}: Leering Gargoyle gets -2/+2 and loses flying until end of turn.

Eland Umbra

Enchant creature
Enchanted creature gets +0/+4.
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Slagwurm Armor

Equipped creature gets +0/+6.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

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.)

Brainstorm

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

Deserted Beach

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

Flaming Fist

Commander creatures you own have "Whenever this creature attacks, it gains double strike until end of turn."

Adarkar Sentinel

{1}: Adarkar Sentinel gets +0/+1 until end of turn.

Island

Djinn of Infinite Deceits

Flying
{T}: Exchange control of two target nonlegendary creatures. You can't activate this ability during combat.

Angel of Destiny

Flying, double strike
Whenever a creature you control deals combat damage to a player, you and that player each gain that much life.
At the beginning of your end step, if you have at least 15 life more than your starting life total, each player Angel of Destiny attacked this turn loses the game.

Mystery Key

When equipped creature deals combat damage to a player, sacrifice Mystery Key. If you do, draw three cards.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Fellwar Stone

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

Sigil of Sleep

Enchant creature
Whenever enchanted creature deals damage to a player, return target creature that player controls to its owner's hand.

Honor Guard

{W}: Honor Guard gets +0/+1 until end of turn.

Aarakocra Sneak

Flying
When Aarakocra Sneak enters, you take the initiative.

True Conviction

Creatures you control have double strike and lifelink.

Wall of Mourning

Defender
When Wall of Mourning enters, exile a card from the top of your library face down for each opponent you have.
Coven — At the beginning of your end step, if you control three or more creatures with different powers, put a card exiled with Wall of Mourning into its owner's hand.

Adarkar Wastes

{T}: Add {C}.
{T}: Add {W} or {U}. Adarkar Wastes deals 1 damage to you.

Bar the Door

Creatures you control get +0/+4 until end of turn.

Robe of the Archmagi

Whenever equipped creature deals combat damage to a player, you draw that many cards.
Equip {4}
Equip Shaman, Warlock, or Wizard {1}

Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Curious Obsession

Enchant creature
Enchanted creature gets +1/+1 and has "Whenever this creature deals combat damage to a player, you may draw a card."
At the beginning of your end step, if you didn't attack with a creature this turn, sacrifice Curious Obsession.

Kabuto Moth

Flying
{T}: Target creature gets +1/+2 until end of turn.

Cut a Deal

Each opponent draws a card, then you draw a card for each opponent who drew a card this way.

Dawn

Aftermath (Cast this spell only from your graveyard. Then exile it.)
Return all creature cards with power 2 or less from your graveyard to your hand.

Dusk

Destroy all creatures with power 3 or greater.

Dusk // Dawn

Gilded Lotus

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Accorder's Shield

Equipped creature gets +0/+3 and has vigilance. (Attacking doesn't cause it to tap.)
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Plains

Deprive

As an additional cost to cast this spell, return a land you control to its owner's hand.
Counter target spell.

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.

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.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Skycloud Expanse

Giant's Amulet

When Giant's Amulet enters, you may pay {3}{U}. If you do, create a 4/4 blue Giant Wizard creature token, then attach Giant's Amulet to it.
Equipped creature gets +0/+1 and has "This creature has hexproof as long as it's untapped." (It can't be the target of spells or abilities your opponents control.)
Equip {2}

Weathered Sentinels

Defender, vigilance, reach, trample
Weathered Sentinels can attack players who attacked you during their last turn as though it didn't have defender.
Whenever Weathered Sentinels attacks, it gets +3/+3 and gains indestructible until end of turn.

Sentinel

{0}: Change Sentinel's base toughness to 1 plus the power of target creature blocking or blocked by Sentinel. (This effect lasts indefinitely.)

Genestealer Locus

Neurotraumal Rod — Whenever a creature attacks you, it gets -1/-0 until end of turn.
Whenever a creature attacks one of your opponents, it gets +0/+1 until end of turn.

Confound

Counter target spell that targets a creature.
Draw a card.

Shield of the Righteous

Equipped creature gets +0/+2 and has vigilance.
Whenever equipped creature blocks a creature, that creature doesn't untap during its controller's next untap step.
Equip {2}

Arcane Signet

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

Living Armor

{T}, Sacrifice Living Armor: Put X +0/+1 counters on target creature, where X is that creature's mana value.

Aegis Turtle

Magus of the Tabernacle

All creatures have "At the beginning of your upkeep, sacrifice this creature unless you pay {1}."

Cloudcrest Lake

{T}: Add {C}.
{T}: Add {W} or {U}. Cloudcrest Lake doesn't untap during your next untap step.

Manriki-Gusari

Equipped creature gets +1/+2 and has "{T}: Destroy target Equipment."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Healer's Headdress

Equipped creature gets +0/+2 and has "{T}: Prevent the next 1 damage that would be dealt to any target this turn."
{W}{W}: Attach Healer's Headdress to target creature you control.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Great Defender

Target creature gets +0/+X until end of turn, where X is its mana value.

Goggles of Night

Whenever equipped creature deals combat damage to a player, scry 1, then draw a card. (To scry 1, look at the top card of your library, then you may put that card on the bottom.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)