Mystic Veil

A protection trick disguised as an Aura, built around a clever piece of timing rules text. The flash clause is what makes it work: you flash it onto your creature as a burn spell or removal is about to resolve, granting shroud so that spell loses its target, and the self-sacrifice at the next cleanup step means the rescue leaves no lasting residue. This is the trade at the heart of the design. Either way you spend one card to negate one spell, a clean one-for-one; the problem with a shroud Aura that sticks around is not card economy but that it walls off your own removal targeting, equip, combat tricks, and any other Aura you might want on that creature. By making the shroud temporary when cast at instant speed, the card sidesteps that lockout and reads as a counterspell-for-creatures rather than an enchantment you commit to. The fine print rewards a second look: the sacrifice penalty only triggers when you cast it any time a sorcery couldn't have been cast. Played on your own main phase, it behaves like an ordinary shroud Aura and stays put. So the same card is two tools depending on the window you use it in: a permanent protective enchantment at sorcery speed, or a one-shot fog-the-target rescue at instant speed. That conditional self-sacrifice is the design discipline doing the balancing work, and it predates the modern habit of stapling drawbacks to flashed-in permanents.