Have

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.

Lyev Skyknight

Flying
When Lyev Skyknight enters, detain target nonland permanent an opponent controls. (Until your next turn, that permanent can't attack or block and its activated abilities can't be activated.)

Meddling Mage

As Meddling Mage enters, choose a nonland card name.
Spells with the chosen name can't be cast.

Temple of Enlightenment

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {W} or {U}.

Dungeon Delver

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

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.

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.

Detention Sphere

When Detention Sphere enters, you may exile target nonland permanent not named Detention Sphere and all other permanents with the same name as that permanent.
When Detention Sphere leaves the battlefield, return the exiled cards to the battlefield under their owner's control.

Mistmeadow Witch

{2}{W}{U}: Exile target creature. Return that card to the battlefield under its owner's control at the beginning of the next end step.

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.)

Ephara's Enlightenment

Enchant creature
When Ephara's Enlightenment enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has flying.
Whenever a creature you control enters, you may return Ephara's Enlightenment to its owner's hand.

Hallowed Respite

Exile target nonlegendary creature, then return it to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on it. Otherwise, tap it.
Flashback {1}{W}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Hama Pashar, Ruin Seeker

Room abilities of dungeons you own trigger an additional time.

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.)

Azorius Chancery

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

Island

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.)

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.)

Prairie Stream

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

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.

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}.

Azorius Guildgate

This land enters tapped.
{T}: Add {W} or {U}.

Augury Adept

Whenever Augury Adept deals combat damage to a player, reveal the top card of your library and put that card into your hand. You gain life equal to its mana value.

Command Tower

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

Deputy of Detention

When Deputy of Detention enters, exile target nonland permanent an opponent controls and all other nonland permanents that player controls with the same name as that permanent until Deputy of Detention leaves the battlefield.

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.

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.

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.)

Fieldmist Borderpost

You may pay {1} and return a basic land you control to its owner's hand rather than pay this spell's mana cost.
Fieldmist Borderpost enters tapped.
{T}: Add {W} or {U}.

Bar the Gate

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

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.

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.)

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.)

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."

Secret Door

Defender
{4}{U}: 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.")

Plains

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.)

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.)

Aven Mimeomancer

Flying
At the beginning of your upkeep, you may put a feather counter on target creature. If you do, that creature has base power and toughness 3/1 and has flying for as long as it has a feather counter on it.

Dovin, Grand Arbiter

+1: Until end of turn, whenever a creature you control deals combat damage to a player, put a loyalty counter on Dovin, Grand Arbiter.
−1: Create a 1/1 colorless Thopter artifact creature token with flying. You gain 1 life.
−7: Look at the top ten cards of your library. Put three of them into your hand and the rest on the bottom of your library in a random order.