Soar

Most flying auras of this vintage were the simplest thing in the set: pay a little blue, grant evasion, attack. What sets this one apart is the conditional flash attached to a buff that ordinarily would have no business being cast at instant speed. Slip it onto a creature during your own main phase and the wings stay; flash it in to ambush an attacker, push the last points of damage, or float a creature over a clogged ground board, and the enchantment doesn't survive to your next turn. The permanent is the toll for the early window.

That timing rule is the whole balance point, and it is unusually transparent for an era when flash-adjacent effects were either priced steeply or simply not permitted off-window. The +0/+1 and flying are nothing; the design lives entirely in whether you cast the aura on schedule or out of it. Played as a sorcery, it is a permanent evasion grant of the kind decks ran by the armful. Played reactively, it converts into a one-shot combat instrument, renting flight for a single turn and reclaiming nothing afterward. It is a clean early example of a card whose entire identity bends around when you cast it rather than what it does, the friction stated openly on the card instead of buried in a cost.