Walker of the Wastes

({C} represents colorless mana.)
Trample
Walker of the Wastes gets +1/+1 for each land you control named Wastes.

Cryptic Caves

{T}: Add {C}.
{1}, {T}, Sacrifice Cryptic Caves: Draw a card. Activate only if you control five or more lands.

Spatial Contortion

({C} represents colorless mana.)
Target creature gets +3/-3 until end of turn.

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.

Tomb of the Spirit Dragon

{T}: Add {C}.
{2}, {T}: You gain 1 life for each colorless creature you control.

Endbringer

Untap Endbringer during each other player's untap step.
{T}: Endbringer deals 1 damage to any target.
{C}, {T}: Target creature can't attack or block this turn.
{C}{C}, {T}: Draw a card.

Wastes

Hedron Crawler

{T}: Add {C}. ({C} represents colorless mana.)

Bane of Bala Ged

Whenever Bane of Bala Ged attacks, defending player exiles two permanents they control.

Ugin, the Ineffable

Colorless spells you cast cost {2} less to cast.
+1: Exile the top card of your library face down and look at it. Create a 2/2 colorless Spirit creature token. When that token leaves the battlefield, put the exiled card into your hand.
−3: Destroy target permanent that's one or more colors.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Reality Smasher

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

Thought-Knot Seer

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

Blast Zone

Blast Zone enters with a charge counter on it.
{T}: Add {C}.
{X}{X}, {T}: Put X charge counters on Blast Zone.
{3}, {T}, Sacrifice Blast Zone: Destroy each nonland permanent with mana value equal to the number of charge counters on Blast Zone.

Pillar of Origins

As Pillar of Origins enters, choose a creature type.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Matter Reshaper

({C} represents colorless mana.)
When Matter Reshaper dies, reveal the top card of your library. You may put that card onto the battlefield if it's a permanent card with mana value 3 or less. Otherwise, put that card into your hand.