Eldrazi Mimic

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

Endless One

Endless One enters with X +1/+1 counters on it.

Mana Confluence

{T}, Pay 1 life: Add one mana of any color.

Spatial Contortion

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

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.

Wastes

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.

Memnite

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.

Mind Stone

{T}: Add {C}.
{1}, {T}, Sacrifice Mind Stone: Draw a card.

Ornithopter

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.

Eldrazi Temple

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

Walker of the Wastes

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