Urza's Workshop

{T}: Add {C}.
Metalcraft — {T}: Add {C} for each Urza's land you control. Activate only if you control three or more artifacts.

Thought-Knot Seer

({C} represents colorless mana.)
When this creature enters, target opponent reveals their hand. You choose a nonland card from it and exile that card.
When this creature leaves the battlefield, target opponent draws a card.

Unwinding Clock

Untap all artifacts you control during each other player's untap step.

Jhoira's Familiar

Flying
Historic spells you cast cost {1} less to cast. (Artifacts, legendaries, and Sagas are historic.)

Mystic Forge

You may look at the top card of your library any time.
You may cast artifact spells and colorless spells from the top of your library.
{T}, Pay 1 life: Exile the top card of your library.

Blight Herder

When you cast this spell, you may put two cards your opponents own from exile into their owners' graveyards. If you do, create three 1/1 colorless Eldrazi Scion creature tokens. They have "Sacrifice this token: Add {C}."

Ulamog's Crusher

Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)
This creature attacks each combat if able.

Planar Bridge

{8}, {T}: Search your library for a permanent card, put it onto the battlefield, then shuffle.

Kozilek's Channeler

Geode Golem

Trample
Whenever this creature deals combat damage to a player, you may cast your commander from the command zone without paying its mana cost. (You still pay any additional costs.)

Metalwork Colossus

This spell costs {X} less to cast, where X is the total mana value of noncreature artifacts you control.
Sacrifice two artifacts: Return this card from your graveyard to your hand.

Darksteel Monolith

Indestructible
Once each turn, you may pay {0} rather than pay the mana cost for a colorless spell you cast from your hand.

Skittering Invasion

Create five 0/1 colorless Eldrazi Spawn creature tokens. They have "Sacrifice this token: Add {C}."

Buried Ruin

{T}: Add {C}.
{2}, {T}, Sacrifice this land: Return target artifact card from your graveyard to your hand.

Quicksilver Amulet

{4}, {T}: You may put a creature card from your hand onto the battlefield.

Desecrate Reality

For each opponent, exile up to one target permanent that player controls with an even mana value. (Zero is even.)
Adamant — If at least three colorless mana was spent to cast this spell, return a permanent card with an odd mana value from your graveyard to the battlefield.

Hand of Emrakul

You may sacrifice four Eldrazi Spawn rather than pay this spell's mana cost.
Annihilator 1 (Whenever this creature attacks, defending player sacrifices a permanent of their choice.)

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Font of Mythos

At the beginning of each player's draw step, that player draws two additional cards.

Breaker of Armies

All creatures able to block this creature do so.

Titan's Presence

As an additional cost to cast this spell, reveal a colorless creature card from your hand.
Exile target creature if its power is less than or equal to the revealed card's power.

Gruesome Slaughter

Until end of turn, colorless creatures you control gain "{T}: This creature deals damage equal to its power to target creature."

Bane of Bala Ged

Whenever this creature attacks, defending player exiles two permanents they control.

Eldrazi Mimic

Whenever another colorless creature you control enters, you may change this creature's base power and toughness to that creature's power and toughness until end of turn.

Rise of the Eldrazi

This spell can't be countered.
Destroy target permanent. Target player draws four cards. Take an extra turn after this one.
Exile Rise of the Eldrazi.

Walking Atlas

{T}: You may put a land card from your hand onto the battlefield.

Zhulodok, Void Gorger

Colorless spells you cast from your hand with mana value 7 or greater have "Cascade, cascade." (When you cast one, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Then do it again.)

Eternal Scourge

You may cast this card from exile.
When this creature becomes the target of a spell or ability an opponent controls, exile this creature.