Flayer Drone

Devoid (This card has no color.)
First strike
Whenever another colorless creature you control enters, target opponent loses 1 life.

Herald of Kozilek

Devoid (This card has no color.)
Colorless spells you cast cost {1} less to cast.

Forsaken Monument

Colorless creatures you control get +2/+2.
Whenever you tap a permanent for {C}, add an additional {C}.
Whenever you cast a colorless spell, you gain 2 life.

Vile Aggregate

Devoid (This card has no color.)
Vile Aggregate's power is equal to the number of colorless creatures you control.
Trample
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)

All Is Dust

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

Slivdrazi Monstrosity

Eldrazi you control are Slivers in addition to their other types.
Slivers you control have devoid and annihilator 1.
{3}: Create a 1/1 colorless Eldrazi Sliver creature token. It has "Sacrifice this creature: Add {C}."

Molten Nursery

Devoid (This card has no color.)
Whenever you cast a colorless spell, Molten Nursery deals 1 damage to any target.

Nettle Drone

Devoid (This card has no color.)
{T}: Nettle Drone deals 1 damage to each opponent.
Whenever you cast a colorless spell, untap Nettle Drone.