Ray of Frost

A hoser dressed as an Aura. Most single-color sideboard hate arrives as a static tax or a damage spell; this instead staples itself to the offending creature and, when that creature is red, shuts it down from three directions at once: it taps the thing on entry to blank a swing, strips its abilities (a hasty attacker or a pinger reduced to vanilla stats), and locks it out of ever untapping. Against anything that is not red, the color-gated clauses simply do not fire: no entry tap, no ability-loss, just the standing "doesn't untap during its controller's untap step" line, which freezes the creature only if it happened to be tapped when the Aura went on. That asymmetry is the whole point. The full lock is reserved for the matchup it was built to punish, while the leftover mode is a modest tempo speed bump rather than an Icy Manipulator that tucks any creature to bed. Flash is what makes the red-hosing mode viable, letting it ambush a threat the moment it commits rather than telegraphing the answer a turn early. The lineage is old white-and-blue "loses all abilities" neutralization welded to a permanent tap-down, then gated behind a color check so the ceiling only appears where it is earned. Sharp against the color it names; something closer to a mediocre Aura against everything else.