You Are Already Dead

Destroy target creature that was dealt damage this turn.
Draw a card.

Crashing Tide

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

Mist-Cloaked Herald

Slither Blade

Twisted Embrace

Enchant artifact or creature you control
When Twisted Embrace enters, destroy target creature or planeswalker an opponent controls.
As long as enchanted permanent is a creature, it gets +1/+1.

Silvergill Adept

As an additional cost to cast this spell, reveal a Merfolk card from your hand or pay {3}.
When Silvergill Adept enters, draw a card.

Winds of Rebuke

Return target nonland permanent to its owner's hand. Each player mills two cards.

Waterknot

Enchant creature
When Waterknot enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.

Snapping Drake

Flying (This creature can't be blocked except by creatures with flying or reach.)

Blighted Bat

Flying
{1}: Blighted Bat gains haste until end of turn.

Triton Waverider

Constellation — Whenever an enchantment you control enters, Triton Waverider gains flying until end of turn.

Doom Blade

Riverwise Augur

When Riverwise Augur enters, draw three cards, then put two cards from your hand on top of your library in any order.

Thieving Magpie

Flying (This creature can't be blocked except by creatures with flying or reach.)
Whenever Thieving Magpie deals damage to an opponent, draw a card.

Ruin Rat

Deathtouch
When Ruin Rat dies, exile target card from an opponent's graveyard.

Aerial Guide

Flying
Whenever Aerial Guide attacks, another target attacking creature gains flying until end of turn.

Satoru Umezawa

Whenever you activate a ninjutsu ability, look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order. This ability triggers only once each turn.
Each creature card in your hand has ninjutsu {2}{U}{B}.

Open into Wonder

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

Floodwaters

Return up to two target creatures to their owners' hands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Kaito's Pursuit

Target player discards two cards. Ninjas and Rogues you control gain menace until end of turn. (They can't be blocked except by two or more creatures.)

Decision Paralysis

Tap up to two target creatures. Those creatures don't untap during their controller's next untap step.

Moon-Circuit Hacker

Ninjutsu {U} ({U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Moon-Circuit Hacker deals combat damage to a player, you may draw a card. If you do, discard a card unless Moon-Circuit Hacker entered this turn.

Spellweaver Eternal

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)

Swamp

Aquatic Incursion

When Aquatic Incursion enters, create two 1/1 blue Merfolk creature tokens with hexproof. (They can't be the targets of spells or abilities your opponents control.)
{3}{U}: Target Merfolk can't be blocked this turn.

Wind Strider

Angler Drake

Flying
When Angler Drake enters, you may return target creature to its owner's hand.

Prosperous Thief

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever one or more Ninja or Rogue creatures you control deal combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Futurist Operative

As long as Futurist Operative is tapped, it's a Human Citizen with base power and toughness 1/1 and can't be blocked.
{2}{U}: Untap Futurist Operative.

Dokuchi Silencer

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Dokuchi Silencer deals combat damage to a player, you may discard a creature card. When you do, destroy target creature or planeswalker that player controls.

Inkrise Infiltrator

Flying
{3}{B}: Inkrise Infiltrator gets +2/+2 until end of turn.

Mukotai Ambusher

Ninjutsu {1}{B} ({1}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Lifelink

Island

Khenra Eternal

Afflict 1 (Whenever this creature becomes blocked, defending player loses 1 life.)

Stern Dismissal

Return target creature or enchantment an opponent controls to its owner's hand.

Fetid Imp

Flying
{B}: Fetid Imp gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Tamiyo's Compleation

Flash
Enchant artifact, creature, or planeswalker
When Tamiyo's Compleation enters, tap enchanted permanent. If it's an Equipment, unattach it.
Enchanted permanent loses all abilities and doesn't untap during its controller's untap step.

Wind Drake

Clawing Torment

Enchant artifact or creature
As long as enchanted permanent is a creature, it gets -1/-1 and can't block.
Enchanted permanent has "At the beginning of your upkeep, you lose 1 life."

Giant Scorpion

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Dokuchi Shadow-Walker

Ninjutsu {3}{B} ({3}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Despoiler of Souls

Despoiler of Souls can't block.
{B}{B}, Exile two other creature cards from your graveyard: Return Despoiler of Souls from your graveyard to the battlefield.

Nezumi Bladeblesser

Nezumi Bladeblesser has deathtouch as long as you control an artifact.
Nezumi Bladeblesser has menace as long as you control an enchantment. (It can't be blocked except by two or more creatures.)

Favorable Winds

Creatures you control with flying get +1/+1.

Cancel

Moonsnare Specialist

Ninjutsu {2}{U} ({2}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
When Moonsnare Specialist enters, return up to one target creature to its owner's hand.

Cursed Minotaur

Menace (This creature can't be blocked except by two or more creatures.)

Eternal of Harsh Truths

Afflict 2 (Whenever this creature becomes blocked, defending player loses 2 life.)
Whenever Eternal of Harsh Truths attacks and isn't blocked, draw a card.

Covert Technician

Ninjutsu {1}{U} ({1}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever Covert Technician deals combat damage to a player, you may put an artifact card with mana value less than or equal to that damage from your hand onto the battlefield.

Wasteland Scorpion

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

Kami of Restless Shadows

When Kami of Restless Shadows enters, choose one —
• Return up to one target Ninja or Rogue creature card from your graveyard to your hand.
• Put target creature card from your graveyard on top of your library.

Daring Saboteur

{2}{U}: Daring Saboteur can't be blocked this turn.
Whenever Daring Saboteur deals combat damage to a player, you may draw a card. If you do, discard a card.