Eldrazi Temple

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless Eldrazi spells or activate abilities of colorless Eldrazi.

Wurmcoil Engine

Deathtouch, lifelink
When this creature dies, create a 3/3 colorless Phyrexian Wurm artifact creature token with deathtouch and a 3/3 colorless Phyrexian Wurm artifact creature token with lifelink.

Breaker of Armies

All creatures able to block this creature do so.

Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Crop Rotation

As an additional cost to cast this spell, sacrifice a land.
Search your library for a land card, put that card onto the battlefield, then shuffle.

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.

Glimmervoid

At the beginning of the end step, if you control no artifacts, sacrifice this land.
{T}: Add one mana of any color.

Deceiver of Form

({C} represents colorless mana.)
At the beginning of combat on your turn, reveal the top card of your library. If a creature card is revealed this way, you may have creatures you control other than this creature become copies of that card until end of turn. You may put that card on the bottom of your library.

Realms Uncharted

Search your library for up to four land cards with different names and reveal them. An opponent chooses two of those cards. Put the chosen cards into your graveyard and the rest into your hand. Then shuffle.

Artisan of Kozilek

When you cast this spell, you may return target creature card from your graveyard to the battlefield.
Annihilator 2 (Whenever this creature attacks, defending player sacrifices two permanents of their choice.)

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Mirage Mirror

{2}: This artifact becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Sylvan Scrying

Search your library for a land card, reveal it, put it into your hand, then shuffle.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Conduit of Ruin

When you cast this spell, you may search your library for a colorless creature card with mana value 7 or greater, reveal it, then shuffle and put that card on top.
The first creature spell you cast each turn costs {2} less to cast.

Expedition Map

{2}, {T}, Sacrifice this artifact: Search your library for a land card, reveal it, put it into your hand, then shuffle.

All Is Dust

Each player sacrifices all permanents they control that are one or more colors.

Forest

Ancient Stirrings

Look at the top five cards of your library. You may reveal a colorless card from among them and put it into your hand. Then put the rest on the bottom of your library in any order.

Reality Smasher

({C} represents colorless mana.)
Trample, haste
Whenever this creature becomes the target of a spell an opponent controls, counter that spell unless its controller discards a card.