Endless Foot Assault

Squad {1}{W} (As an additional cost to cast this spell, you may pay {1}{W} any number of times. When this enchantment enters, create that many tokens that are copies of it.)
Whenever you attack, for each opponent, create a 1/1 black Ninja creature token that's tapped and attacking that player.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Don & Leo, Problem Solvers

Vigilance
At the beginning of your end step, exile up to one target artifact you control and up to one target creature you control. Then return them to the battlefield under their owners' control.

Sakashima of a Thousand Faces

You may have Sakashima enter as a copy of another creature you control, except it has Sakashima's other abilities.
The "legend rule" doesn't apply to permanents you control.
Partner (You can have two commanders if both have partner.)

Silver-Fur Master

Ninjutsu {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Ninjutsu abilities you activate cost {1} less to activate.
Other Ninja and Rogue creatures you control get +1/+1.

Jin Sakai, Ghost of Tsushima

Whenever Jin Sakai deals combat damage to a player, draw a card.
Whenever a creature you control attacks a player, if no other creatures are attacking that player, choose one —
• Standoff — It gains double strike until end of turn.
• Ghost — It can't be blocked this turn.

Turncoat Kunoichi

Sneak {2}{W}{B} (You may cast this spell for {2}{W}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. It enters tapped and attacking.)
When this creature enters, choose target creature an opponent controls. Exile that creature until this creature leaves the battlefield. If this creature's sneak cost was paid, instead exile the chosen creature.

Temple of Enlightenment

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 {W} or {U}.

Make Your Move

Destroy target artifact, enchantment, or creature with power 4 or greater.

Azra Smokeshaper

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.)
When this creature enters, target creature you control gains indestructible until end of turn.

Sinister Hideout

This land enters tapped.
{T}: Add {U} or {B}.
{4}, {T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Blade of Selves

Equipped creature has myriad. (Whenever it attacks, for each opponent other than defending player, you may create a token copy that's tapped and attacking that player or a planeswalker they control. Exile the tokens at end of combat.)
Equip {4}

Super Shredder

Menace
Whenever another permanent leaves the battlefield, put a +1/+1 counter on Super Shredder.

Heirloom Blade

Equipped creature gets +3/+1.
Whenever equipped creature dies, you may reveal cards from the top of your library until you reveal a creature card that shares a creature type with it. Put that card into your hand and the rest on the bottom of your library in a random order.
Equip {1}

Negate

The Last Ronin's Technique

Sneak {1}{W} (You may cast this spell for {1}{W} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Create three 1/1 white Ninja Turtle Spirit creature tokens. If this spell's sneak cost was paid, they enter tapped and attacking.

Command Tower

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

Thousand-Faced Shadow

Ninjutsu {2}{U}{U} ({2}{U}{U}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Flying
When this creature enters from your hand, if it's attacking, create a token that's a copy of another target attacking creature. The token enters tapped and attacking.

Splinter, Hamato Yoshi

Sneak {B} (You may cast this spell for {B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Menace (This creature can't be blocked except by two or more creatures.)
Other Ninjas you control get +1/+1.

Eliminate

Destroy target creature or planeswalker with mana value 3 or less.

Oroku Saki, Shredder Rising

Sneak {1}{B} (You may cast this spell for {1}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Whenever Oroku Saki deals combat damage to a player, you draw a card and lose 1 life.

Dark Leo & Shredder

Sneak {W}{B}
Attacking Ninjas you control have deathtouch.
Whenever Dark Leo & Shredder deal combat damage to a player, create a 1/1 black Ninja creature token. Then if you control five or more Ninjas, that player loses half their life, rounded up.

Sol Ring

Donatello's Technique

Sneak {U} (You may cast this spell for {U} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Draw two cards.

Shredder, Unrelenting

Sneak {3}{B} (You may cast this spell for {3}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Deathtouch
Whenever Shredder enters or attacks, another target creature you control gains deathtouch until end of turn.

Reanimate

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Splinter, Radical Rat

If an ability of a Ninja creature you control triggers, that ability triggers an additional time.
{1}{U}: Target Ninja can't be blocked this turn.

Epic Downfall

Exile target creature with mana value 3 or greater.

Swamp

Saiba Cryptomancer

Flash
Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Hexproof

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Kaito, Cunning Infiltrator

Whenever a creature you control deals combat damage to a player, put a loyalty counter on Kaito.
+1: Up to one target creature you control can't be blocked this turn. Draw a card, then discard a card.
−2: Create a 2/1 blue Ninja creature token.
−9: You get an emblem with "Whenever a player casts a spell, you create a 2/1 blue Ninja creature token."

Impostor Syndrome

Whenever a nontoken creature you control deals combat damage to a player, create a token that's a copy of it, except it isn't legendary.

Arcane Signet

Moonblade Shinobi

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.)
Whenever this creature deals combat damage to a player, create a 1/1 blue Illusion creature token with flying.

Krang & Shredder

Whenever Krang & Shredder enter or attack, each opponent exiles cards from the top of their library until they exile a nonland card.
Disappear — At the beginning of your end step, if a permanent left the battlefield under your control this turn, you may cast a card exiled with Krang & Shredder without paying its mana cost.

Prairie Stream

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

Path of Ancestry

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Whispersilk Cloak

Equipped creature can't be blocked and has shroud. (It can't be the target of spells or abilities.)
Equip {2}

Shredder, Shadow Master

Whenever Shredder attacks a player, for each other opponent, create a token that's a copy of Shredder tapped and attacking that player, except it isn't legendary. Sacrifice those tokens at end of combat.
Whenever Shredder deals combat damage to a player, that player loses half their life, rounded up.

Shredder's Technique

Sneak {B} (You may cast this spell for {B} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Destroy target creature or enchantment. If an enchantment was destroyed this way, you lose 2 life.

Inkrise Infiltrator

Flying
{3}{B}: This creature 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

Shark Shredder, Killer Clone

Sneak {3}{B}{B}
First strike
Whenever Shark Shredder deals combat damage to a player, put up to one target creature card from that player's graveyard onto the battlefield under your control. It enters tapped and attacking that player.

Anguished Unmaking

Exile target nonland permanent. You lose 3 life.

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 token: Add one mana of any color.")

Forsaken Sanctuary

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

Fallen Shinobi

Ninjutsu {2}{U}{B} ({2}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
Whenever this creature deals combat damage to a player, that player exiles the top two cards of their library. Until end of turn, you may play those cards without paying their mana costs.

April O'Neil, Kunoichi Trainee

When April O'Neil enters, 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.)
April O'Neil can't be blocked by creatures with power 3 or greater.

Hylderblade

Equipped creature gets +3/+1.
Void — At the beginning of your end step, if a nonland permanent left the battlefield this turn or a spell was warped this turn, attach this Equipment to target creature you control.
Equip {4} ({4}: Attach to target creature you control. Equip only as a sorcery.)

Vanishing Verse

Splinter, the Mentor

Menace
Whenever Splinter or another nontoken creature you control leaves the battlefield, create a Mutagen token.
Partner—Character select (You can have two commanders if both have this ability.)

Leonardo, Big Brother

Sneak {W} (You may cast this spell for {W} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Leonardo gets +1/+0 for each other creature you control.

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 this creature enters, return up to one target creature to its owner's hand.

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 this creature 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.

The Cloning of Shredder

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Exile target creature card from your graveyard. Create a token that's a copy of it, except it isn't legendary and is a Mutant in addition to its other types.
II, III — Create a token that's a copy of a card exiled with this Saga, except it isn't legendary and is a Mutant in addition to its other types.

Utter End

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}.

Island

Satoru, the Infiltrator

Menace
Whenever Satoru and/or one or more other nontoken creatures you control enter, if none of them were cast or no mana was spent to cast them, draw a card.

Kaito Shizuki

At the beginning of your end step, if Kaito entered this turn, he phases out.
+1: Draw a card. Then discard a card unless you attacked this turn.
−2: Create a 1/1 blue Ninja creature token with "This token can't be blocked."
−7: You get an emblem with "Whenever a creature you control deals combat damage to a player, search your library for a blue or black creature card, put it onto the battlefield, then shuffle."

Deathrender

Equipped creature gets +2/+2.
Whenever equipped creature dies, you may put a creature card from your hand onto the battlefield and attach this Equipment to it.
Equip {2}

Karai, Future of the Foot

Sneak {2}{W}{B} (You may cast this spell for {2}{W}{B} if you also return an unblocked attacker you control to hand during the declare blockers step. She enters tapped and attacking.)
Whenever Karai deals combat damage to a player, return target creature card from your graveyard to your hand. If her sneak cost was paid this turn, instead return that card to the battlefield.

Mirrormind Crown

As long as this Equipment is attached to a creature, the first time you would create one or more tokens each turn, you may instead create that many tokens that are copies of equipped creature.
Equip {2}

Choked Estuary

As this land enters, you may reveal an Island or Swamp card from your hand. If you don't, this land enters tapped.
{T}: Add {U} or {B}.

Urza's Rebuff

Choose one —
• Counter target spell.
• Tap up to two target creatures.

Kaito, Bane of Nightmares

Ninjutsu {1}{U}{B} ({1}{U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)
During your turn, as long as Kaito has one or more loyalty counters on him, he's a 3/4 Ninja creature and has hexproof.
+1: You get an emblem with "Ninjas you control get +1/+1."
0: Surveil 2. Then draw a card for each opponent who lost life this turn.
−2: Tap target creature. Put two stun counters on it.

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 this creature deals combat damage to a player, you may draw a card. If you do, discard a card unless this creature entered this turn.

Yuriko, the Tiger's Shadow

Commander ninjutsu {U}{B} ({U}{B}, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand or the command zone tapped and attacking.)
Whenever a Ninja you control deals combat damage to a player, reveal the top card of your library and put that card into your hand. Each opponent loses life equal to that card's mana value.

Plains

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.)

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Amazing Acrobatics

Choose one or both —
• Counter target spell.
• Tap one or two target creatures.

Ninja Teen

(Gain the next level as a sorcery to add its ability.)
Whenever a creature you control leaves the battlefield, each opponent loses 1 life.
{1}{B}: Level 2
Creatures you control get +1/+0 and have menace.
{B}: Level 3
Creature cards in your graveyard have sneak {3}{B}.
You may cast creature spells from your graveyard using their sneak abilities.