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 Looter

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

Arcane Adaptation

As Arcane Adaptation enters, choose a creature type.
Creatures you control are the chosen type in addition to their other types. The same is true for creature spells you control and creature cards you own that aren't on the battlefield.

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.)

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.

Tamiyo, the Moon Sage

+1: Tap target permanent. It doesn't untap during its controller's next untap step.
−2: Draw a card for each tapped creature target player controls.
−8: You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand."

Cephalid Aristocrat

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

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 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.

Cephalid Scout

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

Borrowing 100,000 Arrows

Draw a card for each tapped creature target opponent controls.

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."

Retraced Image

Reveal a card in your hand, then put that card onto the battlefield if it has the same name as a permanent.

Sol Ring

Cephalid Snitch

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

Cephalid Retainer

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

Cephalid Pathmage

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

Mothdust Changeling

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

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.

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.

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.

Aboshan, Cephalid Emperor

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

Wonder

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

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.

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.

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."

Arcane Signet

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

Cephalid Broker

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

Theft of Dreams

Archetype of Imagination

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

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.