You touch a willing create. The target gains a flying speed of 60 feet and a wing attack option as a bonus action (Proficiency Bonus + Str to hit, 1d8 + Str bludgeoning damage) for the duration. When the spell ends, the target falls if it is still aloft, unless it can stop the fall.

Miscast: On a 18-19 the spell is interrupted with no effects, on a 20 you lose control of the winds of magic that rip through the target's back causing 1d4 bleeding wounds. Each wound causes 1d6 bleeding at the start of the creatures turn and requires a successful medicine check (DC = 14) to be closed. A healing spell gets rid of the bleeding automatically.