When Inside Job enters, target creature can't be blocked this turn.
Whenever you amp it up, return Inside Job to its owner's hand.

When Invader of Privacy enters, surveil 1, then draw a card.

Put a defender counter on each creature.

Flying
Discard a card: Put a +1/+1 counter on Jetstream Cruiser. Activate only once each turn.

When Kappa Colony enters, create three 1/1 green Plant creature tokens.
Whenever you cast a spell from your graveyard, put a +1/+1 counter on each Plant you control.

King of Currents can't attack unless there are six or more cards in your graveyard.
Surface {4}{U}{U}

Enchant creature
When Left to the Sea enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

At the beginning of your end step, scry 1. Then if it's your first turn of the game or you discarded a card named Leystone of Depths this turn, draw a card.
Cycling {U}

Create a 2/2 blue Drake creature token with flying.
Whenever a creature you control enters, if it wandered, you may exile Lofty Frontiers from your graveyard. If you do, create a 2/2 blue Drake creature token with flying.

Put any number of target noncreature cards from your graveyard on top of your library in any order.
Draw a card, then exile Long-Lost Legacy.

Kraken, Leviathan, Octopus, and Serpent spells you cast cost {X} less to cast, where X is your devotion to blue.

Create X blue Shrine enchantment tokens named Unmarked Shrine with “At the beginning of your upkeep, each opponent mills a card.”
{1}{U}, Exile Lost to Memory from your graveyard: Draw two cards. Activate only if an opponent has eight or more cards in their graveyard.

{2}: Target creature gets +0/+3 until end of turn. Activate only as a sorcery and only once each turn.

Put a +1/+1 counter on target creature. It gets +0/+2 until end of turn.

Sacrifice a Treasure: Put a loyalty counter on Marilye, Dreaming Big.
[+1]: Draw a card, then discard a card. If you discarded a nonland card this way, create a tapped Treasure token.
[–3]: Gain control of target artifact. It becomes a Treasure artifact, loses all other types, and loses all abilities except for activated mana abilities.
[–8]: Target opponent chooses a nonland permanent they control. You gain control of the rest.

When Masked Duo enters, tap up to one target creature. If you control an artifact, that creature doesn't untap during its controller's next untap step.

Create two 1/1 blue Wizard creature tokens with prowess.

Whenever you draw your second card each turn, scry 1 then put a +1/+1 counter on Melancholic Oracle.

Target artifact or creature's owner puts it on the top or bottom of their library.
Flashback {5}{U}{U}

Flying
{5}: Draw a card. Activate only if your devotion to blue is three or greater.

Return target creature or enchantment to its owner's hand. If that permanent's controller has eight or more cards in their graveyard, its owner puts it on the top or bottom of their library instead.

Tap up to two target creatures. Put a stun counter on each of them.

Whenever Music Master attacks, you may pay {U}. If you do, put a curio counter on another target creature you control.
{1}{U}: Target creature gains flying until end of turn.

Flying
Creatures you control but don't own get +1/+1 and have flying.
Whenever a creature you control deals combat damage to a player, you may return it to its owner's hand.