Sky Scourer

Devoid (This card has no color.)
Flying
Whenever you cast a colorless spell, Sky Scourer gets +1/+0 until end of turn.

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.

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.

Dominator Drone

Devoid (This card has no color.)
Ingest (Whenever this creature deals combat damage to a player, that player exiles the top card of their library.)
When Dominator Drone enters, if you control another colorless creature, each opponent loses 2 life.

Cultivator Drone

Devoid (This card has no color.)
{T}: Add {C}. Spend this mana only to cast a colorless spell, activate an ability of a colorless permanent, or pay a cost that contains {C}. ({C} represents colorless mana.)