Dusakamakron, The Unbound

Each nonland card in your hand, library, exile
graveyard, and battlefield has Devoid (a Devoid
card has no color).
At the beginning of your upkeep, create a 1/1
colorless Voidwraith creature token with: "When
this creature enters the battlefield, choose a color,
it can't be blocked by creatures of the chosen
color." and haste, sacrifice it at the beginning of
your next end step.