No Mercy

Whenever a creature deals damage to you, destroy it.

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.)

Coral Barrier

Defender (This creature can't attack.)
When Coral Barrier enters, create a 1/1 blue Squid creature token with islandwalk. (It can't be blocked as long as defending player controls an Island.)

Drift of Phantasms

Defender (This creature can't attack.)
Flying
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Wall of Vapor

Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Vapor by creatures it's blocking.

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.")

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.)

Thassa, Deep-Dwelling

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature.
At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control.
{3}{U}: Tap another target creature.

Vertigo Spawn

Defender
Whenever Vertigo Spawn blocks a creature, tap that creature. That creature doesn't untap during its controller's next untap step.

Rilsa Rael, Kingpin

Deathtouch
When Rilsa Rael, Kingpin enters, 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.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Wall of Tears

Defender (This creature can't attack.)
Whenever Wall of Tears blocks a creature, return that creature to its owner's hand at end of combat.

From the Catacombs

Put target creature card from a graveyard onto the battlefield under your control with a corpse counter on it. You take the initiative. If that creature would leave the battlefield, exile it instead of putting it anywhere else.
Escape—{3}{B}{B}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Revealing Eye

Menace
When this creature transforms into Revealing Eye, target opponent reveals their hand. You may choose a nonland card from it. If you do, that player discards that card, then draws a card.

Concealing Curtains

Defender
{2}{B}: Transform Concealing Curtains. Activate only as a sorcery.

Concealing Curtains // Revealing Eye

Wall of Air

Defender, flying (This creature can't attack, and it can block creatures with flying.)

Secret Door

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

Fates' Reversal

Return up to one target creature card from your graveyard to your hand. Venture into the dungeon. (Enter the first room or advance to the next room.)

Baleful Strix

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

Damnation

Destroy all creatures. They can't be regenerated.

Ornithopter of Paradise

Dungeon Delver

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

Hover Barrier

Gomazoa

Defender, flying
{T}: Put Gomazoa and each creature it's blocking on top of their owners' libraries, then those players shuffle.

Ravenloft Adventurer

When Ravenloft Adventurer enters, you take the initiative.
If a creature an opponent controls would die, instead exile it and put a hit counter on it.
Whenever Ravenloft Adventurer attacks, if you've completed a dungeon, defending player loses 1 life for each card they own in exile with a hit counter on it.

Wall of Shadows

Defender (This creature can't attack.)
Prevent all damage that would be dealt to Wall of Shadows by creatures it's blocking.
Wall of Shadows can't be the target of spells that can target only Walls or of abilities that can target only Walls.

Bitterblossom

At the beginning of your upkeep, you lose 1 life and create a 1/1 black Faerie Rogue creature token with flying.

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.)

Propaganda

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

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Crashing Drawbridge

Defender
{T}: Creatures you control gain haste until end of turn.

Toxic Deluge

As an additional cost to cast this spell, pay X life.
All creatures get -X/-X until end of turn.

Psychic Membrane

Defender (This creature can't attack.)
Whenever Psychic Membrane blocks, you may draw a card.

Guard Gomazoa

Defender, flying
Prevent all combat damage that would be dealt to Guard Gomazoa.

Crawlspace

No more than two creatures can attack you each combat.

Petty Theft

Return target nonland permanent an opponent controls to its owner's hand.

Brazen Borrower

Flash
Flying
Brazen Borrower can block only creatures with flying.

Brazen Borrower // Petty Theft

Suspicious Bookcase

Defender
{3}, {T}: Target creature can't be blocked this turn.

Wall of Frost

Defender
Whenever Wall of Frost blocks a creature, that creature doesn't untap during its controller's next untap step.

Silent Arbiter

No more than one creature can attack each combat.
No more than one creature can block each combat.

Fog Bank

Defender (This creature can't attack.)
Flying
Prevent all combat damage that would be dealt to and dealt by this creature.