Endless One

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

Kozilek's Sentinel

Devoid (This card has no color.)
Whenever you cast a colorless spell, Kozilek's Sentinel gets +1/+0 until end of turn.

Touch of the Void

Devoid (This card has no color.)
Touch of the Void deals 3 damage to any target. If a creature dealt damage this way would die this turn, exile it instead.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Barrage Tyrant

Devoid (This card has no color.)
{2}{R}, Sacrifice another colorless creature: Barrage Tyrant deals damage equal to the sacrificed creature's power to any target.

Molten Nursery

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

Swamp

Wasteland Strangler

Devoid (This card has no color.)
When Wasteland Strangler enters the battlefield, you may put a card an opponent owns from exile into that player's graveyard. If you do, target creature gets -3/-3 until end of turn.

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.)

Complete Disregard

Devoid (This card has no color.)
Exile target creature with power 3 or less.

Forerunner of Slaughter

Devoid (This card has no color.)
{1}: Target colorless creature gains haste until end of turn.

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.

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.