Eldrazi Displacer

The colorless activation cost is the whole engine here, and it cuts both ways. Tying a repeatable blink to means the card asks you to build a manabase that produces colorless mana on purpose, which is a real deckbuilding tax in most decks but a near-free upgrade in any deck already running Eldrazi-flavored fixing. Pay that tax and the body becomes one of the cleanest abuse targets ever printed: it blinks anything, not just your own, so it doubles as removal that taps down an attacker, resets an opponent's blocker, or simply re-triggers every enters-the-battlefield ability you control on demand. The return-tapped clause is the discipline on it: the creature comes back vulnerable and out of position, which is what stops the ability from being a strictly-better flicker. Pair it with a creature whose ETB is a hard answer (a Wisp-style bounce, a Flametongue-style burn, anything that kills on arrival) and you have a soft lock that recurs every turn the colorless mana flows. Devoid is the wrapper that makes all of this legal as a white card while keeping it off-color, a quiet acknowledgment that this is Eldrazi machinery dressed in white robes rather than a white card in the traditional sense. The rate (a 3/3 for ) is incidental; the card is sold entirely on the loop, and the loop is gated by a mana type rather than a once-per-turn clause, which is what makes it scale.