Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.

Against All Odds

Choose one or both —
• Exile target artifact or creature you control, then return it to the battlefield under its owner's control.
• Return target artifact or creature card with mana value 3 or less from your graveyard to the battlefield.

Atomic Microsizer

Equipped creature gets +1/+0.
Whenever equipped creature attacks, choose up to one target creature. That creature can't be blocked this turn and has base power and toughness 1/1 until end of turn.
Equip {2}

Shore Up

Target creature you control gets +1/+1 and gains hexproof until end of turn. Untap it. (It can't be the target of spells or abilities your opponents control.)

Sleep with the Fishes

Enchant creature
When this Aura enters, tap enchanted creature and you create a 1/1 blue Fish creature token with "This token can't be blocked."
Enchanted creature doesn't untap during its controller's untap step.

Micromancer

When this creature enters, you may search your library for an instant or sorcery card with mana value 1, reveal it, put it into your hand, then shuffle.

Segovian Angel

Disdainful Stroke

Counter target spell with mana value 4 or greater.

Scrabbling Skullcrab

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, target player mills two cards. (They put the top two cards of their library into their graveyard.)

Exotic Pets

Create two 1/1 blue Fish creature tokens with "This token can't be blocked." Then for each kind of counter among creatures you control, put a counter of that kind on either of those tokens.

Illvoi Galeblade

Flash
Flying
{2}, Sacrifice this creature: Draw a card.

Gods Willing

Target creature you control gains protection from the color of your choice until end of turn. (It can't be blocked, targeted, dealt damage, enchanted, or equipped by anything of that color.)
Scry 1.

Caetus, Sea Tyrant of Segovia

Noncreature spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a noncreature spell pays for {1} or one mana of that creature's color.)
At the beginning of your end step, untap up to four target creatures.

Invasion of Segovia

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, create two 1/1 blue Kraken creature tokens with trample.

Invasion of Segovia // Caetus, Sea Tyrant of Segovia

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

Kasmina's Transmutation

Enchant creature
Enchanted creature loses all abilities and has base power and toughness 1/1.

Bellowing Crier

When this creature enters, draw a card, then discard a card.

Triton Shorestalker

Piranha Fly

Dive Down

Target creature you control gets +0/+3 and gains hexproof until end of turn. (It can't be the target of spells or abilities your opponents control.)

Hedron Crab

Landfall — Whenever a land you control enters, target player mills three cards. (They put the top three cards of their library into their graveyard.)

Scout for Survivors

Return up to three target creature cards with total mana value 3 or less from your graveyard to the battlefield. Put a +1/+1 counter on each of them.

Brineborn Cutthroat

Flash (You may cast this spell any time you could cast an instant.)
Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on this creature.

Assemble the Players

You may look at the top card of your library any time.
Once each turn, you may cast a creature spell with power 2 or less from the top of your library.

Tetsuko Umezawa, Fugitive

Creatures you control with power or toughness 1 or less can't be blocked.

Deepwater Hypnotist

Inspired — Whenever this creature becomes untapped, target creature an opponent controls gets -3/-0 until end of turn.

Kiora, the Rising Tide

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Getting

Dour Port-Mage

Whenever one or more other creatures you control leave the battlefield without dying, draw a card.
{1}{U}, {T}: Return another target creature you control to its owner's hand.

Godhead of Awe

Flying
Other creatures have base power and toughness 1/1.

Raise the Past

Return all creature cards with mana value 2 or less from your graveyard to the battlefield.

Slaughter the Strong

Each player chooses any number of creatures they control with total power 4 or less, then sacrifices all other creatures they control.

Aegis Turtle

Sigiled Starfish

{T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)