Don & Raph, Hard Science

Menace
Whenever Don & Raph attack, the next noncreature spell you cast this turn has affinity for artifacts. (It costs {1} less to cast for each artifact you control.)

Chrome Dome

Other artifact creatures you control get +1/+0.
{5}: Create a token that's a copy of another target artifact you control. That token gains haste. Sacrifice it at the beginning of the next end step.

Puca's Eye

When this artifact enters, draw a card, then choose a color. This artifact becomes the chosen color.
{3}, {T}: Draw a card. Activate only if there are five colors among permanents you control.

Staff of Compleation

{T}, Pay 1 life: Destroy target permanent you own.
{T}, Pay 2 life: Add one mana of any color.
{T}, Pay 3 life: Proliferate.
{T}, Pay 4 life: Draw a card.
{5}: Untap this artifact.

Command Tower

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

TCRI Building

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

Quick-Draw Katana

During your turn, equipped creature gets +2/+0 and has first strike. (It deals combat damage before creatures without first strike.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

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.

Bender's Waterskin

Untap this artifact during each other player's untap step.
{T}: Add one mana of any color.

Henchbots

When this creature enters, exile target tapped creature an opponent controls until this creature leaves the battlefield.

Kappa Cannoneer

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for {1}.)
Ward {4}
Whenever this creature or another artifact you control enters, put a +1/+1 counter on this creature. It can't be blocked this turn.

Shivan Dragon

Flying
{R}: This creature gets +1/+0 until end of turn.

Negate

Item Shopkeep

Whenever you attack, target attacking equipped creature gains menace until end of turn. (It can't be blocked except by two or more creatures.)

Purple Dragon Punks

{T}: Add {R}. Spend this mana only to cast an artifact spell or to activate an ability.

Sage of the Unknowable

{T}: Add {C}. Spend this mana only to cast a colorless spell or to activate an ability.

Noggle the Mind

Flash
Enchant creature
Enchanted creature loses all abilities and is a colorless Noggle with base power and toughness 1/1. (It loses all colors and all other creature types.)

Turtle Van

Whenever this Vehicle attacks, put a +1/+1 counter on target creature that crewed it this turn. Then if that creature is a Mutant, Ninja, or Turtle, double the number of +1/+1 counters on it.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Cool but Rude

(Gain the next level as a sorcery to add its ability.)
Whenever you attack, you may discard a card. If you do, draw a card.
{1}{R}: Level 2
Whenever you discard a card, this Class deals 2 damage to each opponent.
{1}{R}: Level 3
When this Class becomes level 3, search your library for a card, put it into your hand, shuffle, then discard a card at random.

Mountain

Refute

Counter target spell. Draw a card, then discard a card.

Island

Manhole Missile

Manhole Missile deals 3 damage to target creature. You may put a card from your hand on the bottom of your library. If you do, draw a card.

Command Beacon

{T}: Add {C}.
{T}, Sacrifice this land: Put your commander into your hand from the command zone.

Inspiring Statuary

Nonartifact spells you cast have improvise. (Your artifacts can help cast those spells. Each artifact you tap after you're done activating mana abilities pays for {1}.)

Donatello, Turtle Techie

When Donatello enters, if you control an artifact, draw a card.

Price of Freedom

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

Lasting Tarfire

At the beginning of each end step, if you put a counter on a creature this turn, this enchantment deals 2 damage to each opponent.

Raphael's Technique

Sneak {2}{R} (You may cast this spell for {2}{R} if you also return an unblocked attacker you control to hand during the declare blockers step.)
Each player may discard their hand and draw seven cards.

Donatello, Way with Machines

Flying
Whenever an artifact you control enters, put a +1/+1 counter on Donatello.

Metalhead

When Metalhead enters, return up to one other target artifact or creature to its owner's hand.
{R}, Sacrifice another artifact: Put a +1/+1 counter on Metalhead. He gains menace and haste until end of turn.

Thriving Isle

This land enters tapped. As it enters, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Adventurer's Airship

Flying
Whenever this Vehicle attacks, draw a card, then discard a card.
Crew 2 (Tap any number of creatures you control with total power 2 or more: This Vehicle becomes an artifact creature until end of turn.)

Sol Ring

Watcher of the Wayside

When this creature enters, target player mills two cards. You gain 2 life. (To mill two cards, a player puts the top two cards of their library into their graveyard.)

Buzz Bots

Flying, vigilance
When this creature dies, draw a card.

Fugitive Droid

This creature can't be blocked if an artifact entered the battlefield under your control this turn.
{U}, Sacrifice this creature: Counter target spell that targets an artifact or creature you control.

Raphael, Most Attitude

Menace (This creature can't be blocked except by two or more creatures.)
Alliance — Whenever another creature you control enters, you may exile the top card of your library.
Whenever Raphael attacks, until end of turn, you may play a card exiled with Raphael.

Impolite Entrance

Target creature gains trample and haste until end of turn.
Draw a card.

Ray Fillet, Man Ray

Flying
When Ray Fillet enters, create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")
{2}, Remove a +1/+1 counter from a creature you control: Draw a card.

Flush Out

Discard a card. If you do, draw two cards. (Then shuffle this card into its owner's library.)

Stormshriek Feral

Flying, haste
{1}{R}: This creature gets +1/+0 until end of turn.

Stormshriek Feral // Flush Out

Ravenous Robots

Whenever you cast an artifact spell, create a 1/1 colorless Robot artifact creature token.
{R}, {T}: Creature tokens you control gain haste until end of turn.

Krang, Utrom Warlord

Flying, trample, indestructible, haste
Other artifact creatures you control have flying, trample, indestructible, and haste.

Burning Curiosity

As an additional cost to cast this spell, you may blight 1. (You may put a -1/-1 counter on a creature you control.)
Exile the top two cards of your library. If this spell's additional cost was paid, exile the top three cards instead. Until the end of your next turn, you may play those cards.

Baxter Stockman

When Baxter Stockman enters, create a 1/1 colorless Robot artifact creature token.
At the beginning of combat on your turn, target artifact creature you control gets +3/+0 and gains first strike and vigilance until end of turn.

Nobody

When this creature enters, return up to one other target artifact you control to its owner's hand. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Glamer Gifter

Flash
Flying
When this creature enters, choose up to one other target creature. Until end of turn, that creature has base power and toughness 4/4 and gains all creature types.

Raphael, Tough Turtle

Alliance — Whenever another creature you control enters, Raphael deals 1 damage to target opponent.

Zuko, Exiled Prince

Firebending 3 (Whenever this creature attacks, add {R}{R}{R}. This mana lasts until end of combat.)
{3}: Exile the top card of your library. You may play that card this turn.

Solar Transformer

This artifact enters tapped.
When this artifact enters, you get {E}{E}{E} (three energy counters).
{T}: Add {C}.
{T}, Pay {E}: Add one mana of any color.

Waterbending Scroll

{6}, {T}: Draw a card. This ability costs {1} less to activate for each Island you control.

Skateboard

When this Equipment enters, tap target permanent.
Equipped creature gets +1/+0 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Thriving Bluff

This land enters tapped. As it enters, choose a color other than red.
{T}: Add {R} or one mana of the chosen color.

Mouser Mark III

This creature can't attack unless you control another artifact.

Donatello, Mutant Mechanic

{T}: Put three +1/+1 counters on target artifact you control. If it isn't a creature, it becomes a 0/0 Robot creature in addition to its other types. Activate only as a sorcery.
Whenever an artifact you control is put into a graveyard from the battlefield, if it had counters on it, put those counters on up to one target artifact or creature you control.

Ooze Spill

Counter target spell. Create a Mutagen token. (It's an artifact with "{1}, {T}, Sacrifice this token: Put a +1/+1 counter on target creature. Activate only as a sorcery.")

Sokka, Bold Boomeranger

When Sokka enters, discard up to two cards, then draw that many cards.
Whenever you cast an artifact or Lesson spell, put a +1/+1 counter on Sokka.

Improvised Arsenal

Equipped creature gets +1/+0 for each artifact you control.
{4}{R}: Create a token that's a copy of this Equipment.
Equip {R}

Mai, Jaded Edge

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
Exhaust — {3}: Put a double strike counter on Mai. (Activate each exhaust ability only once.)

Hard-Won Jitte

Equipped creature has double strike.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Summit Sentinel

Abandon Attachments

You may discard a card. If you do, draw two cards.

Blasphemous Act

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

Does Machines

(Gain the next level as a sorcery to add its ability.)
When this Class enters, mill two cards, draw two cards, then discard two cards.
{1}{U}: Level 2
When this Class becomes level 2, return up to two target artifact cards from your graveyard to your hand.
{4}{U}: Level 3
At the beginning of combat on your turn, put three +1/+1 counters on target artifact you control. If it isn't a creature, it becomes a 0/0 Robot creature in addition to its other types.

Casey Jones, Jury-Rig Justiciar

Haste
When Casey Jones enters, look at the top four cards of your library. You may reveal an artifact card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Unwelcome Sprite

Flying
Whenever you cast a spell during an opponent's turn, surveil 2. (Look at the top two cards of your library. You may put any number of them into your graveyard and the rest on top of your library in any order.)

Mirror Shield

Equipped creature gets +0/+2 and has hexproof and "Whenever a creature with deathtouch blocks or becomes blocked by this creature, destroy that creature."
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Run Away Together

Choose two target creatures controlled by different players. Return those creatures to their owners' hands.

Benevolent River Spirit

As an additional cost to cast this spell, waterbend {5}. (While paying a waterbend cost, you can tap your artifacts and creatures to help. Each one pays for {1}.)
Flying, ward {2} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {2}.)
When this creature enters, scry 2.

Stalactite Dagger

When this Equipment enters, create a 1/1 colorless Shapeshifter creature token with changeling. (It's every creature type.)
Equipped creature gets +1/+1 and is all creature types.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)