Thought Scour

Target player mills two cards.
Draw a card.

Vapor Snag

Return target creature to its owner's hand. Its controller loses 1 life.

Avatar of Discord

({B/R} can be paid with either {B} or {R}.)
Flying
When Avatar of Discord enters, sacrifice it unless you discard two cards.

Censor

Counter target spell unless its controller pays {1}.
Cycling {U} ({U}, Discard this card: Draw a card.)

Fallaji Archaeologist

When Fallaji Archaeologist enters, mill three cards. You may put a noncreature, nonland card from among the cards milled this way into your hand. If you don't, put a +1/+1 counter on Fallaji Archaeologist. (To mill a card, put the top card of your library into your graveyard.)

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Island

Steamcore Scholar

Flying, vigilance
When Steamcore Scholar enters, draw two cards. Then discard two cards unless you discard an instant or sorcery card or a creature card with flying.

Counterspell

Forbidden Orchard

{T}: Add one mana of any color.
Whenever you tap Forbidden Orchard for mana, target opponent creates a 1/1 colorless Spirit creature token.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Gandalf's Sanction

Gandalf's Sanction deals X damage to target creature, where X is the number of instant and sorcery cards in your graveyard. Excess damage is dealt to that creature's controller instead.

Horribly Awry

Devoid (This card has no color.)
Counter target creature spell with mana value 4 or less. If that spell is countered this way, exile it instead of putting it into its owner's graveyard.

Wall of Lost Thoughts

Defender (This creature can't attack.)
When Wall of Lost Thoughts enters, target player mills four cards. (They put the top four cards of their library into their graveyard.)

Tome Scour

Memory Sluice

Target player mills four cards.
Conspire (As you cast this spell, you may tap two untapped creatures you control that share a color with it. When you do, copy it and you may choose a new target for the copy.)

Countervailing Winds

Counter target spell unless its controller pays {1} for each card in your graveyard.
Cycling {2} ({2}, Discard this card: Draw a card.)

Emergence Zone

{T}: Add {C}.
{1}, {T}, Sacrifice Emergence Zone: You may cast spells this turn as though they had flash.

Gandalf the Grey

Whenever you cast an instant or sorcery spell, choose one that hasn't been chosen —
• You may tap or untap target permanent.
• Gandalf the Grey deals 3 damage to each opponent.
• Copy target instant or sorcery spell you control. You may choose new targets for the copy.
• Put Gandalf on top of its owner's library.

Mirror-Mad Phantasm

Flying
{1}{U}: Mirror-Mad Phantasm's owner shuffles it into their library. If that player does, they reveal cards from the top of that library until a card named Mirror-Mad Phantasm is revealed. The player puts that card onto the battlefield and all other cards revealed this way into their graveyard.

Shenanigans

Destroy target artifact.
Dredge 1 (If you would draw a card, you may mill a card instead. If you do, return this card from your graveyard to your hand.)

Insectile Aberration

Delver of Secrets

At the beginning of your upkeep, look at the top card of your library. You may reveal that card. If an instant or sorcery card is revealed this way, transform Delver of Secrets.

Delver of Secrets // Insectile Aberration

Hieroglyphic Illumination

Draw two cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

Spirebluff Canal

Spirebluff Canal enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.