Hidden Cataract

This land enters tapped.
{T}: Add {U}.
{4}{U}, {T}, Sacrifice this land: Discover 4. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 4 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Gravelgill Duo

Whenever you cast a blue spell, this creature gets +1/+1 until end of turn.
Whenever you cast a black spell, this creature gains fear until end of turn. (It can't be blocked except by artifact creatures and/or black creatures.)

Escape Tunnel

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice this land: Target creature with power 2 or less can't be blocked this turn.

Sleight of Hand

Look at the top two cards of your library. Put one of them into your hand and the other on the bottom of your library.

Dimir Aqueduct

This land enters tapped.
When this land enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Swamp

River Herald Scout

When this creature enters, it explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)

Thassa's Bounty

Draw three cards. Target player mills three cards.

Maximum Overdrive

Put a +1/+1 counter on target creature. It gains deathtouch and indestructible until end of turn.

Evolving Wilds

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Floodpits Drowner

Flash
Vigilance
When this creature enters, tap target creature an opponent controls and put a stun counter on it.
{1}{U}, {T}: Shuffle this creature and target creature with a stun counter on it into their owners' libraries.

Coerced to Kill

Enchant creature
You control enchanted creature.
Enchanted creature has base power and toughness 1/1, has deathtouch, and is an Assassin in addition to its other types.

Fading Hope

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Rot-Tide Gargantua

Exploit (When this creature enters, you may sacrifice a creature.)
When this creature exploits a creature, each opponent sacrifices a creature of their choice.

Treno, Dark City

This land enters tapped.
{T}: Add {U} or {B}.

Dimir Guildgate

Dismal Backwater

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {B}.

Temple of Deceit

This land enters tapped.
When this land enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}: Add {U} or {B}.

Last Gasp

Target creature gets -3/-3 until end of turn.

Kopala, Warden of Waves

Spells your opponents cast that target a Merfolk you control cost {2} more to cast.
Abilities your opponents activate that target a Merfolk you control cost {2} more to activate.

Spell Stutter

Counter target spell unless its controller pays {2} plus an additional {1} for each Faerie you control.

Murder

Mistvault Bridge

This land enters tapped.
Indestructible
{T}: Add {U} or {B}.

Merfolk of the Pearl Trident

Crashing Tide

This spell has flash as long as you control a Merfolk.
Return target creature to its owner's hand.
Draw a card.

Windrider Patrol

Flying
Whenever this creature deals combat damage to a player, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Island

Triton Shorethief

Rootwater Mystic

{1}{U}: Look at the top card of target player's library.

Malice

Destroy target nonblack creature. It can't be regenerated.

Spite

Spite // Malice

Vodalian Soldiers

Catacomb Slug

Contaminated Aquifer

({T}: Add {U} or {B}.)
This land enters tapped.

Dreams of Laguna

Surveil 1, then draw a card. (To surveil 1, look at the top card of your library. You may put it into your graveyard.)
Flashback {3}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

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.

Sahagin

Whenever you cast a noncreature spell, if at least four mana was spent to cast it, put a +1/+1 counter on this creature and it can't be blocked this turn.

Stab Wound

Enchant creature
Enchanted creature gets -2/-2.
At the beginning of the upkeep of enchanted creature's controller, that player loses 2 life.

Towering-Wave Mystic

Whenever this creature deals damage, target player mills that many cards.

Tyrant's Scorn

Choose one —
• Destroy target creature with mana value 3 or less.
• Return target creature to its owner's hand.

Manta Riders

{U}: This creature gains flying until end of turn.

Vohar, Vodalian Desecrator

{T}: Draw a card, then discard a card. If you discarded an instant or sorcery card this way, each opponent loses 1 life and you gain 1 life.
{2}, Sacrifice Vohar: You may cast target instant or sorcery card from your graveyard this turn. If that spell would be put into your graveyard, exile it instead. Activate only as a sorcery.

Quench

Counter target spell unless its controller pays {2}.

Bounce Off

Return target creature or Vehicle to its owner's hand.

Hidden Grotto

When this land enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Add {C}.
{1}, {T}: Add one mana of any color.

Skywatcher Adept

Level up {3} ({3}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-2
2/2
Flying
LEVEL 3+
4/2
Flying

Merrow Grimeblotter

{1}{U/B}, {Q}: Target creature gets -2/-0 until end of turn. ({Q} is the untap symbol.)

Dimir Signet

Sunken Hollow

({T}: Add {U} or {B}.)
This land enters tapped unless you control two or more basic lands.

Wall of Water

Defender (This creature can't attack.)
{U}: This creature gets +1/+0 until end of turn.

Sol Ring

Submerged Boneyard

Murky Sewer

This land enters tapped unless a player has 13 or less life.
{T}: Add {U} or {B}.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Summon: Leviathan

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Return each creature that isn't a Kraken, Leviathan, Merfolk, Octopus, or Serpent to its owner's hand.
II, III — Until end of turn, whenever a Kraken, Leviathan, Merfolk, Octopus, or Serpent attacks, draw a card.
Ward {2}

Dutiful Return

Return up to two target creature cards from your graveyard to your hand.

Vampiric Rites

{1}{B}, Sacrifice a creature: You gain 1 life and draw a card.

Lash of the Balrog

As an additional cost to cast this spell, sacrifice a creature or pay {4}.
Destroy target creature.

Benthic Criminologists

Whenever this creature enters or attacks, you may sacrifice an artifact. If you do, draw a card.

Dreadwurm

Landfall — Whenever a land you control enters, this creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Spreading Seas

Enchant land
When this Aura enters, draw a card.
Enchanted land is an Island.

Ink Dissolver

Kinship — At the beginning of your upkeep, you may look at the top card of your library. If it shares a creature type with this creature, you may reveal it. If you do, each opponent mills three cards.

Waterfront District

This land enters tapped.
{T}: Add {U} or {B}.
{2}{U}{B}, {T}, Sacrifice this land: Draw a card.

Merfolk Coralsmith

{1}: This creature gets +1/-1 until end of turn.
When this creature dies, scry 2.

Negate

Soothsayer Adept

{1}{U}, {T}: Draw a card, then discard a card.

Quick Study

Library Larcenist

Whenever this creature attacks, draw a card.

Aether Gale

Return six target nonland permanents to their owners' hands.

Moonlit Scavengers

When this creature enters, if you control an artifact or enchantment, return target creature an opponent controls to its owner's hand.

Heartless Pillage

Target opponent discards two cards.
Raid — If you attacked this turn, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Deadly Embrace

Destroy target creature an opponent controls. Then draw a card for each creature that died this turn.

Scroll Thief

Whenever this creature deals combat damage to a player, draw a card.

Vodalian Mage

{U}, {T}: Counter target spell unless its controller pays {1}.

Slice from the Shadows

This spell can't be countered. (This includes by the ward ability.)
Target creature gets -X/-X until end of turn.

Cancel

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")

Tainted Isle

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

Enclave Cryptologist

Level up {1}{U} ({1}{U}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-2
0/1
{T}: Draw a card, then discard a card.
LEVEL 3+
0/1
{T}: Draw a card.

Sandbar Merfolk

Cycling {2} ({2}, Discard this card: Draw a card.)

Salvager of Secrets

When this creature enters, return target instant or sorcery card from your graveyard to your hand.