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.

Shellshock

For each opponent, choose up to one target creature that player controls. Shellshock deals X damage to each of those creatures. You create a Mutagen token for each creature dealt damage this way. (They're artifacts with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Raph & Leo, Sibling Rivals

Whenever Raph & Leo attack, if it's the first combat phase of the turn, untap one or two target attacking creatures. After this phase, there is an additional combat phase.

Leatherhead, Iron Gator

Trample, haste
Whenever Leatherhead attacks, put two +1/+1 counters on each creature you control.

Opulent Palace

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

Continue?

Choose up to four target creature cards in your graveyard that were put there from the battlefield this turn. Return them to the battlefield.

Corpsejack Menace

If one or more +1/+1 counters would be put on a creature you control, twice that many +1/+1 counters are put on it instead.

Level Up

Enchant creature
When this Aura enters, put a +1/+1 counter on enchanted creature.
Enchanted creature has "Whenever this creature attacks, double the number of +1/+1 counters on it. Then if it has power 10 or greater, draw a card."

The Ooze

Whenever a creature you control with a +1/+1 counter on it leaves the battlefield, create a Mutagen token for each +1/+1 counter on it. (A Mutagen token is an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")
{T}: Exile target card from a graveyard. Create a Mutagen token.

Rockfall Vale

This land enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Raphael, the Muscle

Double all damage that creatures you control with counters on them would deal.
When Raphael enters, create a Mutagen token.
Partner—Character select (You can have two commanders if both have this ability.)

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Sol Ring

Sodden Verdure

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

Rocksteady, Mutant Marauder

Partner with Bebop, Skull & Crossbones (When this creature enters, target player may put Bebop into their hand from their library, then shuffle.)
Trample
Whenever another nontoken creature you control enters, put a +1/+1 counter on target creature.

Sandsteppe Citadel

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

Forest

Baxter, Fly in the Ointment

Whenever Baxter enters or attacks, each creature you control with a counter on it gains flying until end of turn.
Whenever you draw a card, put a +1/+1 counter on Baxter.

Cinder Glade

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

Urban Retreat

This land enters tapped.
{T}: Add {G}, {W}, or {U}.
{2}, Return a tapped creature you control to its owner's hand: Put this card from your hand onto the battlefield. Activate only as a sorcery.

Michelangelo, the Heart

Trample
Raid (the Fridge) — At the beginning of your second main phase, if you attacked this turn, put a +1/+1 counter on target creature and create a Food token.
Partner—Character select (You can have two commanders if both have this ability.)

Drowned Catacomb

This land enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Wave Goodbye

Return each creature without a +1/+1 counter on it to its owner's hand.

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.

Captain Sisay

{T}: Search your library for a legendary card, reveal that card, put it into your hand, then shuffle.

Party Dude

(Gain the next level as a sorcery to add its ability.)
When this Class enters, each player creates a Food token.
{1}{G}: Level 2
Whenever an artifact an opponent controls is put into a graveyard from the battlefield, draw a card.
{4}{G}: Level 3
Whenever one or more of your opponents are attacked, up to one target attacking creature gets +X/+X until end of turn, where X is the number of cards in your hand.

Leonardo, the Balance

Whenever a token you control enters, you may put a +1/+1 counter on each creature you control. Do this only once each turn.
{W}{U}{B}{R}{G}: Creatures you control gain menace, trample, and lifelink until end of turn.
Partner—Character select (You can have two commanders if both have this ability.)

Ninja Pizza

Foods you control have "{T}, Sacrifice this artifact: Add one mana of any color."
At the beginning of your second main phase, create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")

Savage Lands

This land enters tapped.
{T}: Add {B}, {R}, or {G}.

Lita, Little Orphan Amphibian

Alliance — Whenever another creature you control enters, choose one that hasn't been chosen this turn.
• Put a +1/+1 counter on Lita.
• Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
• Scry 1.

Game Over

This spell costs {2} less to cast if a player's life total is less than or equal to half their starting life total.
Destroy all creatures.

Turtle Lair

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Ninja or Turtle spell.
{3}, {T}: Target Ninja or Turtle can't be blocked this turn.

Big Mother Mouser

This creature enters with two +1/+1 counters on it.
Whenever this creature attacks, double the number of +1/+1 counters on it.
When this creature dies, create a number of 1/1 colorless Robot artifact creature tokens equal to the number of +1/+1 counters on this creature.

Raphael, the Nightwatcher

Sneak {1}{R}{R} (You may cast this spell for {1}{R}{R} if you also return an unblocked attacker you control to hand during the declare blockers step. He enters tapped and attacking.)
Attacking creatures you control have double strike.

Smoldering Marsh

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

Vanquish the Horde

This spell costs {1} less to cast for each creature on the battlefield.
Destroy all creatures.

Steelbane Hydra

This creature enters with X +1/+1 counters on it.
{2}{G}, Remove a +1/+1 counter from this creature: Destroy target artifact or enchantment.

High Score

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.
At the beginning of your end step, draw a card if you control a creature with the greatest power among creatures on the battlefield.

Irma, Part-Time Mutant

At the beginning of combat on your turn, Irma becomes a copy of up to one other target creature you control, except her name is Irma, Part-Time Mutant and she has this ability. Then put a +1/+1 counter on her.

Arcade Cabinet

When this artifact enters, put a +1/+1 counter on each of up to four target creatures.
{2}, {T}, Sacrifice a token: Double the number of each kind of counter on target creature.

Undergrowth Stadium

This land enters tapped unless you have two or more opponents.
{T}: Add {B} or {G}.

Assassin's Trophy

Destroy target permanent an opponent controls. Its controller may search their library for a basic land card, put it onto the battlefield, then shuffle.

Mona Lisa, Science Geek

Reach
{T}: Add X mana of any one color, where X is Mona Lisa's power.

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Sunken Hollow

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

Vigor

Trample
If damage would be dealt to another creature you control, prevent that damage. Put a +1/+1 counter on that creature for each 1 damage prevented this way.
When Vigor is put into a graveyard from anywhere, shuffle it into its owner's library.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Dragonskull Summit

This land enters tapped unless you control a Swamp or a Mountain.
{T}: Add {B} or {R}.

Super Combo

Replicate {2} (When you cast this spell, copy it for each time you paid its replicate cost. You may choose new targets for the copies.)
Target creature you control deals damage equal to its power to target creature an opponent controls.

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.)

Harmonize

Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Big Apple, 3 a.m.

This land enters tapped. As it enters, choose a color.
{T}: Add one mana of the chosen color.
{5}, {T}: Create a 1/1 black Rat creature token for each opponent you have.

New Generation's Technique

Sneak {2}{G} (You may cast this spell for {2}{G} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Voracious Hydra

Trample
This creature enters with X +1/+1 counters on it.
When this creature enters, choose one —
• Double the number of +1/+1 counters on this creature.
• This creature fights target creature you don't control.

Biogenic Ooze

When this creature enters, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
{1}{G}{G}{G}: Create a 2/2 green Ooze creature token.

Command Tower

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

Fast Forward

This spell costs {1} less to cast for each opponent you attacked this turn.
Goad all creatures your opponents control. (Until your next turn, those creatures attack each combat if able and attack a player other than you if able.)

Plains

Tempestra, Dame of Games

{2}{R}, {T}, Sacrifice an artifact: Create a token that's a copy of another target creature you control, except it isn't legendary. It gains haste. Sacrifice it at the beginning of the next end step.

Donatello, the Brains

If one or more tokens would be created under your control, those tokens plus a Mutagen token are created instead.
Partner—Character select (You can have two commanders if both have this ability.)

Heroes in a Half Shell

Vigilance, menace, trample, haste
Whenever one or more Mutants, Ninjas, and/or Turtles you control deal combat damage to a player, put a +1/+1 counter on each of those creatures and draw a card.

Hidden Hideout

This land enters tapped.
{T}: Add one mana of any color in your commander's color identity.
{2}, {T}: Target creature you control with a counter on it gains lifelink until end of turn.

Swamp

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.)

Vernal Fen

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

Mountain

Arcane Signet

Casey Jones, Back Alley Brute

Menace
Whenever Casey Jones attacks, put a +1/+1 counter on target attacking creature.
Whenever you put one or more +1/+1 counters on a creature you control, Casey Jones deals that much damage to target opponent.

Jungle Shrine

This land enters tapped.
{T}: Add {R}, {G}, or {W}.

Fabled Passage

{T}, Sacrifice this land: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Then if you control four or more lands, untap that land.

Crystallized Serah

The first legendary creature spell you cast each turn costs {2} less to cast.
Legendary creatures you control get +2/+2.

Serah Farron

The first legendary creature spell you cast each turn costs {2} less to cast.
At the beginning of combat on your turn, if you control two or more other legendary creatures, you may transform Serah Farron.

Serah Farron // Crystallized Serah

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Exotic Orchard

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

Oran-Rief Ooze

When this creature enters, put a +1/+1 counter on target creature you control.
Whenever this creature attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Krang, the All-Powerful

If a player drawing a card causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Whenever a player draws their second card each turn, put a +1/+1 counter on Krang.

Hinterland Harbor

This land enters tapped unless you control a Forest or an Island.
{T}: Add {G} or {U}.

Isshin, Two Heavens as One

If a creature attacking causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Nuka-Cola Vending Machine

{1}, {T}: Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this token: You gain 3 life.")
Whenever you sacrifice a Food, create a tapped Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Ray Fillet, Wave Warrior

Flying
Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever a creature you control with a counter on it deals combat damage to a player, draw a card.

Spire Garden

This land enters tapped unless you have two or more opponents.
{T}: Add {R} or {G}.

Frontier Bivouac

This land enters tapped.
{T}: Add {G}, {U}, or {R}.

Together Forever

When this enchantment enters, support 2. (Put a +1/+1 counter on each of up to two target creatures.)
{1}: Choose target creature with a counter on it. When that creature dies this turn, return that card to its owner's hand.

Here Comes a New Hero!

Target player draws X cards. Create a token that's a copy of up to one target creature with mana value X or less.

Island

Lessons from Life

Draw three cards. You may put a land card from your hand onto the battlefield tapped.

Coin of Mastery

Each creature you control enters with an additional +1/+1 counter on it for each mana from an artifact source spent to cast it.
{T}: Create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")

Michelangelo's Technique

Sneak {3}{G} (You may cast this spell for {3}{G} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Look at the top eight cards of your library. Put up to two creature cards with total mana value 6 or less from among them onto the battlefield and the rest on the bottom of your library in a random order.

Exploding Barrel

{T}: Add one mana of any color. Put a pressure counter on this artifact.
{8}, {T}, Sacrifice this artifact: It deals 20 damage to target creature. This ability costs {1} less to activate for each pressure counter on this artifact. Activate only as a sorcery.

Umbral Mantle

Equipped creature has "{3}, {Q}: This creature gets +2/+2 until end of turn." ({Q} is the untap symbol.)
Equip {0}

Rat King, Pale Piper

Menace
Whenever Rat King or another nontoken creature you control leaves the battlefield, create a 1/1 black Rat creature token.
{2}, Sacrifice a token: Draw a card.

Grand Coliseum

This land enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. This land deals 1 damage to you.