Deep Gnome Terramancer

Flash
Mold Earth — Whenever one or more lands enter under an opponent's control without being played, you may search your library for a Plains card, put it onto the battlefield tapped, then shuffle. Do this only once each turn.

Nymris, Oona's Trickster

Flash
Flying
Whenever you cast your first spell during each opponent's turn, look at the top two cards of your library. Put one of those cards into your hand and the other into your graveyard.

Sea-Dasher Octopus

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Whenever this creature deals combat damage to a player, draw a card.

Aboleth Spawn

Flash
Ward {2}
Probing Telepathy — Whenever a creature entering under an opponent's control causes a triggered ability of that creature to trigger, you may copy that ability. You may choose new targets for the copy.

Faerie Conclave

Faerie Conclave enters tapped.
{T}: Add {U}.
{1}{U}: Faerie Conclave becomes a 2/1 blue Faerie creature with flying until end of turn. It's still a land.

Errant and Giada

Flash
Flying
You may look at the top card of your library any time.
You may cast spells with flash or flying from the top of your library.

Ertai Resurrected

Flash
When Ertai Resurrected enters, choose up to one —
• Counter target spell, activated ability, or triggered ability. Its controller draws a card.
• Destroy another target creature or planeswalker. Its controller draws a card.

Venser, Shaper Savant

Flash (You may cast this spell any time you could cast an instant.)
When Venser, Shaper Savant enters, return target spell or permanent to its owner's hand.

Faerie Tauntings

Whenever you cast a spell during an opponent's turn, you may have each opponent lose 1 life.

Torrential Gearhulk

Flash
When Torrential Gearhulk enters, you may cast target instant card from your graveyard without paying its mana cost. If that spell would be put into your graveyard, exile it instead.

Cunning Nightbonder

Flash
Spells with flash you cast cost {1} less to cast and can't be countered.

Mystical Teachings

Search your library for an instant card or a card with flash, reveal it, put it into your hand, then shuffle.
Flashback {5}{B} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Vendilion Clique

Flash
Flying
When Vendilion Clique enters, look at target player's hand. You may choose a nonland card from it. If you do, that player reveals the chosen card, puts it on the bottom of their library, then draws a card.

Notion Thief

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead that player skips that draw and you draw a card.

Cemetery Protector

Flash
When Cemetery Protector enters, exile a card from a graveyard.
Whenever you play a land or cast a spell, if it shares a card type with the exiled card, create a 1/1 white Human creature token.

Naiad of Hidden Coves

During turns other than yours, spells you cast cost {1} less to cast.

Chromium, the Mutable

Flash
This spell can't be countered.
Flying
Discard a card: Until end of turn, Chromium, the Mutable becomes a Human with base power and toughness 1/1, loses all abilities, and gains hexproof. It can't be blocked this turn.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Spectral Sailor

Flash (You may cast this spell any time you could cast an instant.)
Flying
{3}{U}: Draw a card.

Slitherwisp

Flash
Whenever you cast another spell that has flash, you draw a card and each opponent loses 1 life.

Aven Mindcensor

Flash
Flying
If an opponent would search a library, that player searches the top four cards of that library instead.

Cast Out

Flash
When Cast Out enters, exile target nonland permanent an opponent controls until Cast Out leaves the battlefield.
Cycling {W} ({W}, Discard this card: Draw a card.)