Bigfin Bouncer

When this creature enters, return target creature an opponent controls to its owner's hand.

Scrounging Skyray

Flying
Whenever you discard one or more cards, put that many +1/+1 counters on this creature.
Cycling {2} ({2}, Discard this card: Draw a card.)

Lulu, Stern Guardian

Whenever an opponent attacks you, choose target creature attacking you. Put a stun counter on that creature.
{3}{U}: Proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Razzle-Dazzler

Whenever you cast your second spell each turn, put a +1/+1 counter on this creature. It can't be blocked this turn.

Deepmuck Desperado

Whenever you commit a crime, each opponent mills three cards. This ability triggers only once each turn. (Targeting opponents, anything they control, and/or cards in their graveyards is a crime.)

Step Between Worlds

Each player may shuffle their hand and graveyard into their library. Each player who does draws seven cards. Exile Step Between Worlds.
Plot {4}{U}{U} (You may pay {4}{U}{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.)

Think Twice

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Shifting Grift

Spree (Choose one or more additional costs.)
+ {2} — Exchange control of two target creatures.
+ {1} — Exchange control of two target artifacts.
+ {1} — Exchange control of two target enchantments.

Steamcore Scholar

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

Island

Glimmerburst

Draw two cards. Create a 1/1 white Glimmer enchantment creature token.

Clinquant Skymage

Flying
Whenever you draw a card, put a +1/+1 counter on this creature.

Loan Shark

When this creature enters, if you've cast two or more spells this turn, draw a card.
Plot {3}{U} (You may pay {3}{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.)

Sudden Setback

The owner of target spell or nonland permanent puts it on their choice of the top or bottom of their library.

Unstoppable Plan

At the beginning of your end step, untap all nonland permanents you control.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.