Cerulean Wisps

The color-change clause is the part people overlook, and it is the part that justifies the slot. Untapping a creature and replacing the card is a fine combat trick on its own: ambush a blocker, save an attacker from a tapper, dig one card deeper for a single blue mana. But "becomes blue" is the real lever. In a deck with a payoff that counts how many creatures of a given color it controls, this recolors any creature at instant speed, and it does so cheaply enough to do repeatedly. Where most color-changing effects ride on enchantments or pricier sorceries, this folds the recoloring into a one-mana cantrip that also untaps and draws, so you never spend a card to enable the synergy. That triple function (untap, recolor, replace itself) is the tension it resolves: each clause is marginal alone, but together they let a tribal or color-matters deck pay almost nothing to keep its engine turning. The untap fuels mana-creature taps or tapper loops; the recolor turns an off-color body into a countable blue one for whatever cares about blue creatures; the draw means the operation costs tempo but never a card. Note that recoloring a creature does not touch devotion, which counts mana symbols printed in mana costs and is untouched by a temporary color swap. Hand it to a deck with no reason to care what color its creatures are, and it shrinks back to a cantrip that occasionally surprises an attacker.