Arcane Signet

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

Riptide Replicator

As Riptide Replicator enters, choose a color and a creature type.
Riptide Replicator enters with X charge counters on it.
{4}, {T}: Create an X/X creature token of the chosen color and type, where X is the number of charge counters on Riptide Replicator.

Theft of Dreams

Draw a card for each tapped creature target opponent controls.

Metallic Mimic

As Metallic Mimic enters, choose a creature type.
Metallic Mimic is the chosen type in addition to its other types.
Each other creature you control of the chosen type enters with an additional +1/+1 counter on it.

Aboshan, Cephalid Emperor

Tap an untapped Octopus you control: Tap target permanent.
{U}{U}{U}: Tap all creatures without flying.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Aetherize

Return all attacking creatures to their owner's hand.

Archetype of Imagination

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

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Cryptic Command

Choose two —
• Counter target spell.
• Return target permanent to its owner's hand.
• Tap all creatures your opponents control.
• Draw a card.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Llawan, Cephalid Empress

When Llawan, Cephalid Empress enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Mutavault

{T}: Add {C}.
{1}: Mutavault becomes a 2/2 creature with all creature types until end of turn. It's still a land.

Cowardice

Whenever a creature becomes the target of a spell or ability, return that creature to its owner's hand. (It won't be affected by the spell or ability.)

Dramatic Reversal

Untap all nonland permanents you control.

High Tide

Until end of turn, whenever a player taps an Island for mana, that player adds an additional {U}.

Cephalid Illusionist

Whenever Cephalid Illusionist becomes the target of a spell or ability, mill three cards.
{2}{U}, {T}: Prevent all combat damage that would be dealt to and dealt by target creature you control this turn.

Cephalid Vandal

At the beginning of your upkeep, put a shred counter on Cephalid Vandal. Then mill a card for each shred counter on Cephalid Vandal.

Heraldic Banner

As Heraldic Banner enters, choose a color.
Creatures you control of the chosen color get +1/+0.
{T}: Add one mana of the chosen color.

Cephalid Coliseum

{T}: Add {U}. Cephalid Coliseum deals 1 damage to you.
Threshold — {U}, {T}, Sacrifice Cephalid Coliseum: Target player draws three cards, then discards three cards. Activate only if seven or more cards are in your graveyard.

Wonder

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

Island

Callous Oppressor

You may choose not to untap Callous Oppressor during your untap step.
As Callous Oppressor enters, an opponent chooses a creature type.
{T}: Gain control of target creature that isn't of the chosen type for as long as Callous Oppressor remains tapped.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Time of Ice

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Tap target creature an opponent controls. It doesn't untap during its controller's untap step for as long as you control Time of Ice.
III — Return all tapped creatures to their owners' hands.

Burnished Hart

{3}, Sacrifice Burnished Hart: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Cephalid Pathmage

Cephalid Pathmage can't be blocked.
{T}, Sacrifice Cephalid Pathmage: Target creature can't be blocked this turn.

Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Maskwood Nexus

Creatures you control are every creature type. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.
{3}, {T}: Create a 2/2 blue Shapeshifter creature token with changeling. (It is every creature type.)

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Sword of Hearth and Home

Equipped creature gets +2/+2 and has protection from green and from white.
Whenever equipped creature deals combat damage to a player, exile up to one target creature you own, then search your library for a basic land card. Put both cards onto the battlefield under your control, then shuffle.
Equip {2}

Counterspell

Cephalid Scout

Flying
{2}{U}, Sacrifice a land: Draw a card.

Cephalid Snitch

Sacrifice Cephalid Snitch: Target creature loses protection from black until end of turn.

Amoeboid Changeling

Changeling (This card is every creature type.)
{T}: Target creature gains all creature types until end of turn.
{T}: Target creature loses all creature types until end of turn.

Consuming Tide

Each player chooses a nonland permanent they control. Return all nonland permanents not chosen this way to their owners' hands. Then you draw a card for each opponent who has more cards in their hand than you.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Borrowing 100,000 Arrows

Thought Vessel

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

Cephalid Retainer

{U}{U}: Tap target creature without flying.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Reliquary Tower

Cephalid Inkshrouder

Discard a card: Cephalid Inkshrouder 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.)

Sky Diamond

Sol Ring

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Cephalid Constable

Whenever Cephalid Constable deals combat damage to a player, return up to that many target permanents that player controls to their owner's hand.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Castle Vantress

Castle Vantress enters tapped unless you control an Island.
{T}: Add {U}.
{2}{U}{U}, {T}: Scry 2.

Betrayal

Enchant creature an opponent controls
Whenever enchanted creature becomes tapped, you draw a card.

Cephalid Looter

{T}: Target player draws a card, then discards a card.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Cephalid Sage

Threshold — As long as seven or more cards are in your graveyard, Cephalid Sage has "When Cephalid Sage enters, draw three cards, then discard two cards."

Fact or Fiction

Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Mothdust Changeling

Changeling (This card is every creature type.)
Tap an untapped creature you control: Mothdust Changeling gains flying until end of turn.

Verity Circle

Whenever a creature an opponent controls becomes tapped, if it isn't being declared as an attacker, you may draw a card.
{4}{U}: Tap target creature without flying.

Aboshan's Desire

Enchant creature
Enchanted creature has flying.
Threshold — Enchanted creature has shroud as long as seven or more cards are in your graveyard. (It can't be the target of spells or abilities.)

Cephalid Broker

{T}: Target player draws two cards, then discards two cards.

Universal Automaton

Changeling (This card is every creature type.)

Hedron Archive

{T}: Add {C}{C}.
{2}, {T}, Sacrifice Hedron Archive: Draw two cards.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Shapesharer

Changeling (This card is every creature type.)
{2}{U}: Target Shapeshifter becomes a copy of target creature until your next turn.

Levitation

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Kefnet's Monument

Blue creature spells you cast cost {1} less to cast.
Whenever you cast a creature spell, target creature an opponent controls doesn't untap during its controller's next untap step.

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Cephalid Aristocrat

Whenever Cephalid Aristocrat becomes the target of a spell or ability, mill two cards.