Maybe

Vedalken Blademaster

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Your Temple Is Under Attack

Choose one —
• Pray for Protection — Creatures you control gain indestructible until end of turn.
• Strike a Deal — You and target opponent each draw two cards.

Lost Mine of Phandelver

Cave Entrance — Scry 1. (Leads to: Goblin Lair, Mine Tunnels)
Goblin Lair — Create a 1/1 red Goblin creature token. (Leads to: Storeroom, Dark Pool)
Mine Tunnels — Create a Treasure token. (Leads to: Dark Pool, Fungi Cavern)
Storeroom — Put a +1/+1 counter on target creature. (Leads to: Temple of Dumathoin)
Dark Pool — Each opponent loses 1 life and you gain 1 life. (Leads to: Temple of Dumathoin)
Fungi Cavern — Target creature gets -4/-0 until your next turn. (Leads to: Temple of Dumathoin)
Temple of Dumathoin — Draw a card.

Sejiri Glacier

Sejiri Glacier enters the battlefield tapped.
{T}: Add {W}.

Sejiri Shelter

Target creature you control gains protection from the color of your choice until end of turn.

Sejiri Shelter // Sejiri Glacier

Have

Flood of Recollection

Return target instant or sorcery card from your graveyard to your hand. Exile Flood of Recollection.

Sea Gate

Sea Gate enters the battlefield tapped.
As Sea Gate enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Getting

Fraying Line

When Fraying Line enters the battlefield, put a rope counter on target creature you control.
At the beginning of each player's upkeep, that player may pay {2}. If they do, they put a rope counter on a creature they control. Otherwise, exile Fraying Line and each creature without a rope counter on it, then remove all rope counters from all creatures.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Experimental Augury

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Sculpted Sunburst

Choose a creature you control, then each opponent chooses a creature they control with equal or lesser power. If you chose a creature this way, exile each creature not chosen by any player this way.

Tale of Tinúviel

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Target creature you control gains indestructible for as long as you control Tale of Tinúviel.
II — Return target creature card from your graveyard to the battlefield.
III — Up to two target creatures you control each gain lifelink until end of turn.

Rasaad yn Bashir

Each creature you control assigns combat damage equal to its toughness rather than its power.
Whenever Rasaad yn Bashir attacks, if you have the initiative, double the toughness of each creature you control until end of turn.
Choose a Background (You can have a Background as a second commander.)

Psionic Snoop

Flash
When Psionic Snoop enters the battlefield, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)

Rilsa Rael, Kingpin

Deathtouch
When Rilsa Rael, Kingpin enters the battlefield, you take the initiative.
Whenever you attack, target attacking creature gains deathtouch until end of turn. If you've completed a dungeon, that creature also gets +5/+0 and gains first strike and menace until end of turn.

Displace

Exile up to two target creatures you control, then return those cards to the battlefield under their owner's control.

Meandering River

Meandering River enters the battlefield tapped.
{T}: Add {W} or {U}.

Cloak of the Bat

Equipped creature has flying and haste.
Equip {2} ({2}: 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.)

Desert of the Mindful

Desert of the Mindful enters the battlefield tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

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

Vhal, Candlekeep Researcher

Vigilance
{T}: Add an amount of {C} equal to Vhal, Candlekeep Researcher's toughness. This mana can't be spent to cast spells from your hand.
Choose a Background (You can have a Background as a second commander.)

Raff, Weatherlight Stalwart

Whenever you cast an instant or sorcery spell, you may tap two untapped creatures you control. If you do, draw a card.
{3}{W}{W}: Creatures you control get +1/+1 and gain vigilance until end of turn.

Landroval, Horizon Witness

Flying
Whenever two or more creatures you control attack a player, target attacking creature without flying gains flying until end of turn.

Coastline Chimera

Flying
{1}{W}: Coastline Chimera can block an additional creature this turn.

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.)

Revoke Existence

Safana, Calimport Cutthroat

Menace
At the beginning of your end step, if you have the initiative, create a Treasure token. Create three of those tokens instead if you've completed a dungeon.
Choose a Background (You can have a Background as a second commander.)

Aarakocra Sneak

Flying
When Aarakocra Sneak enters the battlefield, you take the initiative.

Gift of the Fae

Target creature gets +2/+1 and gains flying until end of turn. (Then exile this card. You may cast the creature later from exile.)

Faerie Guidemother

Faerie Guidemother // Gift of the Fae

Decanter of Endless Water

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

Dawnbringer Cleric

When Dawnbringer Cleric enters the battlefield, choose one —
• Cure Wounds — You gain 2 life.
• Dispel Magic — Destroy target enchantment.
• Gentle Repose — Exile target card from a graveyard.

Baleful Strix

Flying, deathtouch
When Baleful Strix enters the battlefield, draw a card.

Fading Hope

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

Serpentine Ambush

Until end of turn, target creature becomes a blue Serpent with base power and toughness 5/5.

Secret Door

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

Dungeon Delver

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

Ertai's Scorn

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

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 of your library.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Sefris of the Hidden Ways

Whenever one or more creature cards are put into your graveyard from anywhere, venture into the dungeon. This ability triggers only once each turn. (To venture into the dungeon, enter the first room or advance to the next room.)
Create Undead — Whenever you complete a dungeon, return target creature card from your graveyard to the battlefield.

Umara Entangler

Dungeon of the Mad Mage

Yawning Portal — You gain 1 life. (Leads to: Dungeon Level)
Dungeon Level — Scry 1. (Leads to: Goblin Bazaar, Twisted Caverns)
Goblin Bazaar — Create a Treasure token. (Leads to: Lost Level)
Twisted Caverns — Target creature can't attack until your next turn. (Leads to: Lost Level)
Lost Level — Scry 2. (Leads to: Runestone Caverns, Muiral's Graveyard)
Runestone Caverns — Exile the top two cards of your library. You may play them. (Leads to: Deep Mines)
Muiral's Graveyard — Create two 1/1 black Skeleton creature tokens. (Leads to: Deep Mines)
Deep Mines — Scry 3. (Leads to: Mad Wizard's Lair)
Mad Wizard's Lair — Draw three cards and reveal them. You may cast one of them without paying its mana cost.

Skybridge Towers

Skybridge Towers enters the battlefield tapped.
{T}: Add {W} or {U}.
{2}{W}{U}, {T}, Sacrifice Skybridge Towers: Draw a card.

Scribe of the Mindful

{1}, {T}, Sacrifice Scribe of the Mindful: Return target instant or sorcery card from your graveyard to your hand.

Veteran Dungeoneer

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

Pixie Dust

Up to three target creatures gain flying until end of turn. (Then exile this card. You may cast the creature later from exile.)

Moonshae Pixie

Flying
When Moonshae Pixie enters the battlefield, draw cards equal to the number of opponents who were dealt combat damage this turn.

Moonshae Pixie // Pixie Dust

Oji, the Exquisite Blade

When Oji, the Exquisite Blade enters the battlefield, you gain 2 life and scry 2.
Whenever you cast your second spell each turn, exile up to one target creature you control, then return it to the battlefield under its owner's control.

Take into Custody

Tap target creature. It doesn't untap during its controller's next untap step.

Runic Shot

Kicker {U} (You may pay an additional {U} as you cast this spell.)
Destroy target tapped creature. If this spell was kicked, scry 2.

Fierce Retribution

Cleave {5}{W} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Destroy target [attacking] creature.

Nadaar, Selfless Paladin

Vigilance
Whenever Nadaar, Selfless Paladin enters the battlefield 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.

Eccentric Apprentice

Flying
When Eccentric Apprentice enters the battlefield, 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.

Void Rend

This spell can't be countered.
Destroy target nonland permanent.

Unsummon

Return target creature to its owner's hand.

Metropolis Sprite

Flying
{U}: Metropolis Sprite gets +1/-1 until end of turn.

Wingcrafter

Soulbond (You may pair this creature with another unpaired creature when either enters the battlefield. They remain paired for as long as you control both of them.)
As long as Wingcrafter is paired with another creature, both creatures have flying.

Herbal Poultice

{3}, Sacrifice Herbal Poultice: Regenerate target creature.

Geistwave

Return target nonland permanent to its owner's hand. If you controlled that permanent, draw a card.

Elminster

Whenever you scry, the next instant or sorcery spell you cast this turn costs {X} less to cast, where X is the number of cards looked at while scrying this way.
+2: Draw a card, then scry 2.
−3: Exile the top card of your library. Create a number of 1/1 blue Faerie Dragon creature tokens with flying equal to that card's mana value.
Elminster can be your commander.

Deny the Divine

Counter target creature or enchantment spell. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Jump

Target creature gains flying until end of turn.

Cloister Gargoyle

When Cloister Gargoyle enters the battlefield, 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.

Angelic Gift

Enchant creature
When Angelic Gift enters the battlefield, draw a card.
Enchanted creature has flying.

Githzerai Monk

Flash
Flying
Psychic Defense — When Githzerai Monk enters the battlefield, tap all creatures you don't control.

Island

Disruption Protocol

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

Kabira Outrider

When Kabira Outrider enters the battlefield, target creature gets +1/+1 until end of turn for each creature in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

Far Traveler

Commander creatures you own have "At the beginning of your end step, exile up to one target tapped creature you control, then return it to the battlefield under its owner's control."

Tome Raider

Flying
When Tome Raider enters the battlefield, draw a card.

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Omenspeaker

When Omenspeaker enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Greatsword of Tyr

Whenever equipped creature attacks, put a +1/+1 counter on it and tap up to one target creature defending player controls.
Equip {W} ({W}: Attach to target creature you control. Equip only as a sorcery.)

Gideon's Reproach

Gideon's Reproach deals 4 damage to target attacking or blocking creature.

You Find the Villains' Lair

Choose one —
• Foil Their Scheme — Counter target spell.
• Learn Their Secrets — Draw two cards, then discard two cards.

Inga Rune-Eyes

When Inga Rune-Eyes enters the battlefield, scry 3.
When Inga Rune-Eyes dies, draw three cards if three or more creatures died this turn.

The Bath Song

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Draw two cards, then discard a card.
III — Shuffle any number of target cards from your graveyard into your library. Add {U}{U}.

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.)

Cancel

Family Reunion

Choose one —
• Creatures you control get +1/+1 until end of turn.
• Creatures you control gain hexproof until end of turn. (They can't be the targets of spells or abilities your opponents control.)

White Plume Adventurer

When White Plume Adventurer enters the battlefield, 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.

Serra Disciple

Flying, first strike
Whenever you cast a historic spell, Serra Disciple gets +1/+1 until end of turn. (Artifacts, legendaries, and Sagas are historic.)

Momentary Blink

Exile target creature you control, then return it to the battlefield under its owner's control.
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Practiced Tactics

Choose target attacking or blocking creature. Practiced Tactics deals damage to that creature equal to twice the number of creatures in your party. (Your party consists of up to one each of Cleric, Rogue, Warrior, and Wizard.)

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.)

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

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.)

Mending Hands

Prevent the next 4 damage that would be dealt to any target this turn.

Alley Evasion

Choose one —
• Target creature you control gets +1/+2 until end of turn.
• Return target creature you control to its owner's hand.

Feywild Caretaker

When Feywild Caretaker enters the battlefield, 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.

Tomb of Annihilation

Trapped Entry — Each player loses 1 life. (Leads to: Veils of Fear, Oubliette)
Veils of Fear — Each player loses 2 life unless they discard a card. (Leads to: Sandfall Cell)
Sandfall Cell — Each player loses 2 life unless they sacrifice a creature, artifact, or land. (Leads to: Cradle of the Death God)
Oubliette — Discard a card and sacrifice a creature, an artifact, and a land. (Leads to: Cradle of the Death God)
Cradle of the Death God — Create The Atropal, a legendary 4/4 black God Horror creature token with deathtouch.

Abuelo, Ancestral Echo

Flying, ward {2}
{1}{W}{U}: Exile another target creature or artifact you control. Return it to the battlefield under its owner's control at the beginning of the next end step.

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.)

True-Faith Censer

Equipped creature gets +1/+1 and has vigilance.
As long as equipped creature is a Human, it gets an additional +1/+0.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Alchemist's Retrieval

Cleave {1}{U} (You may cast this spell for its cleave cost. If you do, remove the words in square brackets.)
Return target nonland permanent [you control] to its owner's hand.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Graceful Reprieve

When target creature dies this turn, return that card to the battlefield under its owner's control.