Sakashima of a Thousand Faces

You may have Sakashima of a Thousand Faces enter as a copy of another creature you control, except it has Sakashima of a Thousand Faces's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Whirler Rogue

When Whirler Rogue enters, create two 1/1 colorless Thopter artifact creature tokens with flying.
Tap two untapped artifacts you control: Target creature can't be blocked this turn.

Curse of Surveillance

Enchant player
At the beginning of enchanted player's upkeep, any number of target players other than that player each draw cards equal to the number of Curses attached to that player.

Triton Wavebreaker

Bestow {1}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached.)
As long as Triton Wavebreaker is a creature, it has prowess. (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Enchanted creature gets +1/+1 and has prowess.

Selhoff Occultist

Whenever Selhoff Occultist or another creature dies, target player mills a card.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Wizard Class

(Gain the next level as a sorcery to add its ability.)
You have no maximum hand size.
{2}{U}: Level 2
When this Class becomes level 2, draw two cards.
{4}{U}: Level 3
Whenever you draw a card, put a +1/+1 counter on target creature you control.

Lethargy Trap

If three or more creatures are attacking, you may pay {U} rather than pay this spell's mana cost.
Attacking creatures get -3/-0 until end of turn.

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Sword Coast Sailor

Commander creatures you own have "Whenever this creature attacks a player, if no opponent has more life than that player, this creature can't be blocked this turn."

Halimar Depths

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Callaphe, Beloved of the Sea

Callaphe's power is equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
Creatures and enchantments you control have "Spells your opponents cast that target this permanent cost {1} more to cast."

Stream of Consciousness

Target player shuffles up to four target cards from their graveyard into their library.

Marchesa's Emissary

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)

Medomai's Prophecy

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after IV.)
I — Scry 2.
II — Choose a card name.
III — When you cast a spell with the chosen name for the first time this turn, draw two cards.
IV — Look at the top card of each player's library.

Curse of Verbosity

Enchant player
Whenever enchanted player is attacked, you draw a card. Each opponent attacking that player does the same.

Wonder

Flying
As long as Wonder is in your graveyard and you control an Island, creatures you control have flying.

Living Breakthrough

Flying
Whenever you cast a spell, your opponents can't cast spells with the same mana value as that spell until your next turn.

Inventive Iteration

(As this Saga enters and after your draw step, add a lore counter.)
I — Return up to one target creature or planeswalker to its owner's hand.
II — Return an artifact card from your graveyard to your hand. If you can't, draw a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Inventive Iteration // Living Breakthrough

Eriette's Tempting Apple

When Eriette's Tempting Apple enters, gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
{2}, {T}, Sacrifice Eriette's Tempting Apple: You gain 3 life.
{2}, {T}, Sacrifice Eriette's Tempting Apple: Target opponent loses 3 life.

Candlekeep Sage

Commander creatures you own have "When this creature enters or leaves the battlefield, draw a card."

Preordain

Scry 2, then draw a card. (To scry 2, look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Nephalia Smuggler

{3}{U}, {T}: Exile another target creature you control, then return that card to the battlefield under your control.

Thassa, God of the Sea

Indestructible
As long as your devotion to blue is less than five, Thassa isn't a creature. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
{1}{U}: Target creature you control can't be blocked this turn.

Gossip's Talent

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control enters, surveil 1.
{1}{U}: Level 2
Whenever you attack, target attacking creature with power 3 or less can't be blocked this turn.
{3}{U}: Level 3
Whenever a creature you control deals combat damage to a player, you may exile it, then return it to the battlefield under its owner's control.

Zulaport Duelist

Flash
When Zulaport Duelist enters, up to one target creature gets -2/-0 until end of turn. Its controller mills two cards. (They put the top two cards of their library into their graveyard.)

Environmental Sciences

Search your library for a basic land card, reveal it, put it into your hand, then shuffle. You gain 2 life.

Slickshot Lockpicker

When Slickshot Lockpicker enters, target instant or sorcery card in your graveyard gains flashback until end of turn. The flashback cost is equal to its mana cost. (You may cast that card from your graveyard for its flashback cost. Then exile it.)
Plot {2}{U} (You may pay {2}{U} and exile this card from your hand. Cast it as a sorcery on a later turn without paying its mana cost. Plot only as a sorcery.)

Thieves' Fortune

Prowl {U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
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.

Notorious Throng

Prowl {5}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Create X 1/1 black Faerie Rogue creature tokens with flying, where X is the damage dealt to your opponents this turn. If this spell's prowl cost was paid, take an extra turn after this one.

Drowned Diner

When you unlock this door, draw three cards, then discard a card.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Meat Locker

When you unlock this door, tap up to one target creature and put two stun counters on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Meat Locker // Drowned Diner

Invisible Stalker

Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Invisible Stalker can't be blocked.

Eidolon of Philosophy

{6}{U}, Sacrifice Eidolon of Philosophy: Draw three cards.

Serum Visions

Reach Through Mists

Slickshot Vault-Buster

Vigilance
Slickshot Vault-Buster gets +2/+0 as long as you've committed a crime this turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Vision of the Unspeakable

Flying, trample
Vision of the Unspeakable gets +1/+1 for each card in your hand.

Behold the Unspeakable

(As this Saga enters and after your draw step, add a lore counter.)
I — Creatures you don't control get -2/-0 until your next turn.
II — If you have one or fewer cards in hand, draw four cards. Otherwise, scry 2, then draw two cards.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Behold the Unspeakable // Vision of the Unspeakable

Veil of Secrecy

Target creature gains shroud until end of turn and can't be blocked this turn. (A creature with shroud can't be the target of spells or abilities.)
Splice onto Arcane—Return a blue creature you control to its owner's hand. (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)

Sanctum of Calm Waters

At the beginning of your first main phase, you may draw X cards, where X is the number of Shrines you control. If you do, discard a card.

Seal of Removal

Sacrifice Seal of Removal: Return target creature to its owner's hand.

Ponder

Look at the top three cards of your library, then put them back in any order. You may shuffle.
Draw a card.

Archetype of Imagination

Creatures you control have flying.
Creatures your opponents control lose flying and can't have or gain flying.

Catlike Curiosity

Enchant creature
Enchanted creature has "Whenever this creature deals combat damage to a player, draw a card."
If Catlike Curiosity would be put into a graveyard from anywhere, exile it instead.

Mischievous Catgeist

Whenever Mischievous Catgeist deals combat damage to a player, draw a card.
Disturb {2}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mischievous Catgeist // Catlike Curiosity

Cut the Earthly Bond

Return target enchanted permanent to its owner's hand.

Brinebarrow Intruder

Flash
When Brinebarrow Intruder enters, target creature an opponent controls gets -2/-0 until end of turn.

Master Thief

When Master Thief enters, gain control of target artifact for as long as you control Master Thief.

Neurok Spy

Neurok Spy can't be blocked as long as defending player controls an artifact.

Blighted Agent

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
Blighted Agent can't be blocked.

Locker Room

Whenever one or more creatures you control deal combat damage to a player, draw a card.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Bottomless Pool

When you unlock this door, return up to one target creature to its owner's hand.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Bottomless Pool // Locker Room

Nimble Brigand

Nimble Brigand can't be blocked if you've committed a crime this turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)
Whenever Nimble Brigand deals combat damage to a player, draw a card.

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Curse of the Bloody Tome

Enchant player
At the beginning of enchanted player's upkeep, that player mills two cards.

Fear of Sleep Paralysis

Flying
Eerie — Whenever Fear of Sleep Paralysis or another enchantment you control enters and whenever you fully unlock a Room, tap up to one target creature and put a stun counter on it.
Stun counters can't be removed from permanents your opponents control. (They won't untap if they have stun counters.)

Hypnotic Siren

Bestow {5}{U}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flying
You control enchanted creature.
Enchanted creature gets +1/+1 and has flying.

Knowledge Exploitation

Prowl {3}{U} (You may cast this for its prowl cost if you dealt combat damage to a player this turn with a Rogue.)
Search target opponent's library for an instant or sorcery card. You may cast that card without paying its mana cost. Then that player shuffles.

Fear of Isolation

As an additional cost to cast this spell, return a permanent you control to its owner's hand.
Flying

Hada Spy Patrol

Level up {2}{U} ({2}{U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-2
2/2
Hada Spy Patrol can't be blocked.
LEVEL 3+
3/3
Shroud (This creature can't be the target of spells or abilities.)
Hada Spy Patrol can't be blocked.

Honden of Seeing Winds

At the beginning of your upkeep, draw a card for each Shrine you control.

Hall of Storm Giants

If you control two or more other lands, Hall of Storm Giants enters tapped.
{T}: Add {U}.
{5}{U}: Until end of turn, Hall of Storm Giants becomes a 7/7 blue Giant creature with ward {3}. It's still a land. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)

Tetsuko Umezawa, Fugitive

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

Curse of Unbinding

Enchant player
At the beginning of enchanted player's upkeep, that player reveals cards from the top of their library until they reveal a creature card. Put that card onto the battlefield under your control. That player puts the rest of the revealed cards into their graveyard.

Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)

Promising Stairs

At the beginning of your upkeep, surveil 1. You win the game if there are eight or more different names among unlocked doors of Rooms you control.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Central Elevator

When you unlock this door, search your library for a Room card that doesn't have the same name as a Room you control, reveal it, put it into your hand, then shuffle.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Central Elevator // Promising Stairs

Dimir Informant

When Dimir Informant enters, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Ghastly Mimicry

Enchant creature
At the beginning of your upkeep, create a token that's a copy of enchanted creature, except it's a Spirit in addition to its other types.
If Ghastly Mimicry would be put into a graveyard from anywhere, exile it instead.

Mirrorhall Mimic

You may have Mirrorhall Mimic enter as a copy of any creature on the battlefield, except it's a Spirit in addition to its other types.
Disturb {3}{U}{U} (You may cast this card from your graveyard transformed for its disturb cost.)

Mirrorhall Mimic // Ghastly Mimicry

Rune of Flight

Enchant permanent
When Rune of Flight enters, draw a card.
As long as enchanted permanent is a creature, it has flying.
As long as enchanted permanent is an Equipment, it has "Equipped creature has flying."

Mascot Exhibition

Create a 2/1 white and black Inkling creature token with flying, a 3/2 red and white Spirit creature token, and a 4/4 blue and red Elemental creature token.

Shameless Charlatan

Commander creatures you own have "{2}{U}: This creature becomes a copy of another target creature."

Mystic Sanctuary

({T}: Add {U}.)
Mystic Sanctuary enters tapped unless you control three or more other Islands.
When Mystic Sanctuary enters untapped, you may put target instant or sorcery card from your graveyard on top of your library.

Psionic Snoop

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

Wings of Velis Vel

Changeling (This card is every creature type.)
Until end of turn, target creature has base power and toughness 4/4, gains all creature types, and gains flying.

Go-Shintai of Lost Wisdom

Flying
At the beginning of your end step, you may pay {1}. When you do, target player mills X cards, where X is the number of Shrines you control. (To mill a card, a player puts the top card of their library into their graveyard.)

Three Bowls of Porridge

{2}, {T}: Choose one that hasn't been chosen —
• Three Bowls of Porridge deals 2 damage to target creature.
• Tap target creature.
• Sacrifice Three Bowls of Porridge. You gain 3 life.

Neurok Commando

Shroud (This creature can't be the target of spells or abilities.)
Whenever Neurok Commando deals combat damage to a player, you may draw a card.

Marchesa's Infiltrator

Dethrone (Whenever this creature attacks the player with the most life or tied for most life, put a +1/+1 counter on it.)
Whenever Marchesa's Infiltrator deals combat damage to a player, draw a card.

Beyeen Coast

Beyeen Coast enters tapped.
{T}: Add {U}.

Beyeen Veil

Creatures your opponents control get -2/-0 until end of turn.

Beyeen Veil // Beyeen Coast

Moonring Island

({T}: Add {U}.)
Moonring Island enters tapped.
{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.

Soporific Springs

As Soporific Springs enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {U}.

Sink into Stupor

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

Sink into Stupor // Soporific Springs

Feywild Visitor

Commander creatures you own have "Whenever one or more nontoken creatures you control deal combat damage to a player, you create a 1/1 blue Faerie Dragon creature token with flying."

Vector Glider

The Modern Age

(As this Saga enters and after your draw step, add a lore counter.)
I, II — Draw a card, then discard a card.
III — Exile this Saga, then return it to the battlefield transformed under your control.

The Modern Age // Vector Glider

Cloak and Dagger

Equipped creature gets +2/+0 and has shroud. (It can't be the target of spells or abilities.)
Whenever a Rogue creature enters, you may attach Cloak and Dagger to it.
Equip {3}

Sakashima the Impostor

You may have Sakashima the Impostor enter as a copy of any creature on the battlefield, except its name is Sakashima the Impostor, it's legendary in addition to its other types, and it has "{2}{U}{U}: Return this creature to its owner's hand at the beginning of the next end step."

Levitation

Snow-Covered Island

Flitterstep Eidolon

Bestow {5}{U} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
Flitterstep Eidolon can't be blocked.
Enchanted creature gets +1/+1 and can't be blocked.

Slimy Aquarium

When you unlock this door, manifest dread, then put a +1/+1 counter on that creature.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Underwater Tunnel

When you unlock this door, surveil 2. (Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.)
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Underwater Tunnel // Slimy Aquarium

Curse of Echoes

Enchant player
Whenever enchanted player casts an instant or sorcery spell, each other player may copy that spell and may choose new targets for the copy they control.