Draw a card. When you do, pay for and choose any number.
+{U} — Return target spell you don't control to its owner's hand. That player draws a card.
+{R} — Target player discards all the cards in their hand, then draws that many cards.
+{G} — Target player may put a land card from their hand or graveyard onto the battlefield.

Target creature gains hexproof until end of turn. Untap it.
Draw a card if your devotion to blue is three or greater.

Flash
Whenever Thassa's Tideshaper attacks, defending player mills two cards and you draw a card. Then discard a card unless defending player has eight or more cards in their graveyard.

[+2]: Each player puts their hand on the bottom of their library in a random order. You draw five cards, then each opponent draws two cards.
[+1]: Untap each land you control.
[–3]: Return up to three target nonland permanents to their owner's hands.
[–9]: You get an emblem with “Whenever an opponent casts their first spell each turn, gain control of it. You may choose new targets for that spell.”

Whenever you cast a noncreature spell, create a 1/1 white Human creature token, then target player mills two cards.

I — Draw two cards.
II — Return all nonland, nonenchantment permanents to their owners' hands.
III — You may cast a non-Saga spell with mana value 5 or less from your hand without paying its mana cost.

Tap all permanents.
Exile The World Stood Still.

Draw a card if a creature you control has flying. Do the same for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

Draw three cards. Then discard two cards unless you discard a card with flashback.
Flashback {6}{U}{U}

Whenever you cast a creature spell, put X depth counters on Tide's Ire, where X is that spell's mana value.
Remove ten depth counters from Tide's Ire: Create an 8/8 blue Kraken creature token.
Remove thirty depth counters from Tide's Ire: Create Tromokratis, a legendary 20/20 blue Kraken creature token with trample and hexproof.

Tidewake Walker enters with a hexproof counter on it.

When Tireless Aspirants enters, you may draw a card. If you do, discard a card.
Wander {1}{U}

Draw two cards.
Up to one target creature gains flying until end of turn.

Target opponent reveals cards from the top of their library until four land cards are revealed. Exile each card revealed this way. If seven or fewer cards were exiled this way, scry 3.

This spell costs {2} less to cast if your devotion to blue is three or greater.
Scry 2, then draw two cards.

Creatures you control can't be blocked unless defending player pays {1} for each creature blocking it.
Creatures can't attack you unless their controller pays {1} for each creature they control that's attacking you.

The first spell you cast each turn costs {2} less to cast.
The second spell you cast each turn can't be countered.
Whenever you cast your third spell each turn, draw a card.

Counter target spell with mana value less than or equal to the number of cards in its controller's graveyard.

Equipped creature gets +1/+0.
Whenever equipped creature attacks, you may cast an instant or sorcery card from your hand with mana value X or less without paying its mana cost, where X is equipped creature's power.
Equip {2}

Once each turn, when you activate a nonmana ability, you may have creatures your opponents control get -1/-0 until end of turn.
{2}: Unnerving Moth gains flying until end of turn.

Golems you control have ward {1}.
Unspeaking Titan can't attack or block unless you control three or more Golems.
Whenever Unspeaking Titan enters or attacks, tap up to one target creature and put a stun counter on it.
{3}, {T}: Create a 1/1 white Golem creature token.

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.

Approval — Counter target noncreature spell unless its controller pays {X}, where X is the number of colors among permanents you control.

At the beginning of your end step, if you control three or more untapped lands, you may exile another target permanent you control, then return it to the battlefield under its owner's control.
{1}{U}{U}: Scry 1.

Enchant creature
Enchanted creature gets +1/+0 and can't be blocked.
{5}{U}, Exile Voyage to the Siren Sea from your graveyard or the battlefield: Draw three cards. This ability costs {1} less for each creature you control that dealt combat damage to an opponent this turn.