Flying

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

{2}{U}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.

Ultimate Sacrifice -- {1}{U}, Sacrifice Adric: Counter target activated or triggered ability.

Doctor's companion (You can have two commanders if the other is the Doctor.)

When Bloodboil Sorcerer enters the battlefield, you take the initiative.

Crown of Madness -- {1}{R}, Sacrifice an artifact or creature: Goad target creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Trample

When Caves of Chaos Adventurer enters the battlefield, you take the initiative.

Whenever Caves of Chaos Adventurer attacks, exile the top card of your library. If you've completed a dungeon, you may play that card this turn without paying its mana cost. Otherwise, you may play that card this turn.

{3}, {T}: Target player puts the bottom card of their library into their graveyard. If it's a creature card, you create a 2/2 black Zombie creature token.

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.

Draw a card.

Reach

{2}, {T}: Put target card from a graveyard on the bottom of its owner's library.

{T}: Add {C}.

{2}, {T}, Sacrifice Demolition Field: Destroy target nonbasic land an opponent controls. That land's controller may search their library for a basic land card, put it onto the battlefield, then shuffle. You may search your library for a basic land card, put it onto the battlefield, then shuffle.

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.)

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

Dungeoneer's Pack enters the battlefield 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.")

{2}: Put target card from your graveyard on the bottom of your library.

At the beginning of your upkeep, scry 1.

{5}{U}: Exchange control of Eyes Everywhere and target nonland permanent. Activate only as a sorcery.

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.

{T}: Add {C}.

{2}, {T}, Sacrifice Field of Ruin: Destroy target nonbasic land an opponent controls. Each player searches their library for a basic land card, puts it onto the battlefield, then shuffles.

Draw two cards, then discard two cards. Untap up to three lands.

Destroy all nonbasic lands. For each land destroyed this way, its controller may search their library for a basic land card and put it onto the battlefield. Then each player who searched their library this way shuffles.

Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Draw a card.

{T}: Add {C}.

{T}, Sacrifice Ghost Quarter: Destroy target land. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

{2}{R}: Reveal cards from the top of your library until you reveal a nonland card. Goblin Machinist gets +X/+0 until end of turn, where X is that card's mana value. Put the revealed cards on the bottom of your library in any order.

When Hired Giant enters the battlefield, each other player may search their library for a land card and put that card onto the battlefield. Then each player who searched their library this way shuffles.

Flying

Ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)

{2}: Put target card from a graveyard on the bottom of its owner's library.

You may pay {2}{U} rather than pay this spell's mana cost.

If the {2}{U} cost was paid, you draw three cards, then an opponent creates two Treasure tokens and they scry 2. If that cost wasn't paid, you draw X cards.

Defender

{T}: Put target card from a graveyard on the bottom of its owner's library.

Flying, trample

When Krenko's Buzzcrusher enters the battlefield, for each player, destroy up to one nonbasic land that player controls. For each land destroyed this way, its controller may search their library for a basic land card, put it onto the battlefield tapped, then shuffle.

{T}: Add one mana of any color.

{4}, {T}: Look at the top card of your library. If it's a land card, you may put it onto the battlefield tapped. If you don't put the card onto the battlefield, you may put it on the bottom of your library.

{2}, {T}: Copy target activated or triggered ability you control. You may choose new targets for the copy.

{3}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy.

{4}, {T}: Copy target permanent spell you control. (The copy becomes a token.)

Whenever you cast a noncreature spell, target creature gets +X/+0 until end of turn, where X is that spell's mana value.

Choose a Background (You can have a Background as a second commander.)

When Loot Dispute enters the battlefield, you take the initiative and create a Treasure token.

Whenever you attack the player who has the initiative, create a Treasure token.

Loud Ruckus -- Whenever you complete a dungeon, create a 5/5 red Dragon creature token with flying.

Reach

{2}, {T}: Put target card from a graveyard on the bottom of its owner's library.

{2}{U}, {T}: Put target creature on the bottom of its owner's library. That creature's controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield and the rest on the bottom of their library in any order. Activate only as a sorcery.

Flash

When Radiant Performer enters the battlefield, if you cast it from your hand, choose target spell or ability that targets only a single permanent or player. Copy that spell or ability for each other permanent or player the spell or ability could target. Each copy targets a different one of those permanents and players.

Put target permanent you own on the bottom of your library. Reveal cards from the top of your library until you reveal a card that shares a card type with that permanent. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

{3}: Put target card from a graveyard on the bottom of its owner's library.

Defender

When Reito Sentinel enters the battlefield, target player mills three cards. (They put the top three cards of their library into their graveyard.)

{3}: Put target card from a graveyard on the bottom of its owner's library.

Meet in Reverse -- You draw cards from the bottom of your library rather than the top.

Spoilers -- Whenever an opponent scries, surveils, or searches their library, put a +1/+1 counter on River Song. Then River Song deals damage to that player equal to its power.

When Sarevok's Tome enters the battlefield, 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.

Defender

When Stirring Bard enters the battlefield, you take the initiative.

Mantle of Inspiration -- {T}: Target creature gains menace and haste until end of turn.

{2}, {T}: Copy target triggered ability you control. You may choose new targets for the copy. (A triggered ability uses the words "when," "whenever," or "at.")

Choose one --

• Counter target spell unless its controller pays {3}.

• 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.

When Tomb of Horrors Adventurer enters the battlefield, 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.)

When Trailblazer's Torch enters the battlefield, 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.)

Whenever Transplant Theorist or another artifact enters the battlefield under your control, you may draw a card. If you do, discard a card.

{2}: Put target card from your graveyard on the bottom of your library.

Reveal the top five cards of your library and separate them into two piles. An opponent chooses one of those piles. Put a card from the chosen pile into your hand, then put all other cards revealed this way on the bottom of your library in any order.

When Vessel of Endless Rest enters the battlefield, put target card from a graveyard on the bottom of its owner's library.

{T}: Add one mana of any color.

{T}: Add {C}.

{1}, {T}, Sacrifice Volatile Fault: Destroy target nonbasic land an opponent controls. That player may search their library for a basic land card, put it onto the battlefield, then shuffle. You create a Treasure token.

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.)