Cryptic Caves

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

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.

Scour from Existence

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.

Ratchet Bomb

{T}: Put a charge counter on Ratchet Bomb.
{T}, Sacrifice Ratchet Bomb: Destroy each nonland permanent with mana value equal to the number of charge counters on Ratchet Bomb.

Sentinel Totem

When Sentinel Totem enters, scry 1. (Look at the top card of your library. You may put that card on the bottom.)
{T}, Exile Sentinel Totem: Exile all graveyards.

Warping Wail

({C} represents colorless mana.)
Choose one —
• Exile target creature with power or toughness 1 or less.
• Counter target sorcery spell.
• Create a 1/1 colorless Eldrazi Scion creature token. It has "Sacrifice this creature: Add {C}."

Hedron Crawler

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

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.

Walker of the Wastes

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

Pithing Needle

As Pithing Needle enters, choose a card name.
Activated abilities of sources with the chosen name can't be activated unless they're mana abilities.

Spatial Contortion

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

Wastes

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.

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.

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.

Ghostfire Blade

Equipped creature gets +2/+2.
Equip {3}
Ghostfire Blade's equip ability costs {2} less to activate if it targets a colorless creature.

Tomb of the Spirit Dragon

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