"Rainbow Dash does something awesome" as the prompt. (Ask Dash fans, get Dash prompts.)
Chill mountain air nibbled through her flightsuit, two kilospans above sea level, but Rainbow Dash felt it only as an abstract twinge blotted out by adrenaline. She circled, up and up, waiting on her cue. Off in the distance, thick streams of smoke coiled around each other like a free-floating sconce.
Come on, Spitfire.
An orange glow burst from the base of the sconce, rising within the smoky confines, up and up in a fast shallow helix. Lighting the torch. Halfway, come on, hit the halfway, halfway up and it's…
Dash dove as only she could, angled to catch the mountain slope. Its white peak thrust at her like a spear, then expanded to fill the bottom of her vision. Mach half, catch it at mach half…
She buzzed the incline a few feet high, adjusted, still gaining speed. Her wake cut streaks in the snow behind. Dash focused, intuiting the backwash as an extension of herself to cup the snow and tug. It resisted for a moment, dragged against its will. Then it began to roll.
Phew. Rolling, it would build naturally, and keep pace – at least a ton of snow by the time it hit the crowd. Just get it fast enough to jump the gorge. An easy ride from there.
The ball grew fast, faster than last time, already twice her size. Every extra flake brought another tug of inertia. Needed more juice. Rainbow gunned it–
And suddenly her wake was free, clear of the ball. Shit. She glanced back, quick, just a moment's peek so as not to spin out. The snowball followed directly behind her, but fallen behind her wake. 'k.
She pitched upwards, bleeding speed as the slope fell away, caught the sun and sky 'below' her as she flipped over. Passed her loop's peak, and back down; the ground closed in seemingly from above, and accelerating descent returned her to speed. She trusted her wings to regain the slope rather than strand her in a snowbank…
Dash came level behind a monstrous mass of rolling snow and dove past it, caught it again in the shockwave of her wake and sped it behind her, back to mach half and now over. The chasm gaped ahead; her snowball struck open air and fell below her, but she fell with it, shepherded it across like a speeding soccer ball. It struck the far slope with a rumbling splut and tore down the mountain's base as if it knew they’d hit the home stretch.
No snow this low. Rather than grow, it left a sleek white streak, shrinking but within the agreed-on size parameters. Ahead, the stands stood in two lanes. Like a bowling ball. Right down the middle.
Dash looped back again and dove in hard. The mach cone seemed to know her plan; it balked, it tugged, it fought, it clung to her in a scintillating sheath of color. It burst right before the stands, drew every eye and gave her an unstoppable rush of speed. She rolled tightly around the ball as she shot past, caught it in a rainbow path and drew it up, up, far above the Appleachian crowd. The rainboom wasn't finished; an overload of pegasus pony power shook and jostled her, demanding release. She gritted her teeth. Keep it together, just a little higher, and–
A ring of every color burst behind her, parallel to the ground, split the snowball into a fine mist that twinkled down to the ground behind her. Dash rose higher, panting, allowed her trail to fade. She disappeared from audience view behind the ‘offstage’ cloud bank and stagger-flapped to lap.
Her hooves touched cloud. A disbelieving grin crept up her face and took possession, spread out from her body in a cackling laugh. Beside her, Fleetfoot giggled, still psyching up for her own solo routine.
A midsummer rainbow flash-snow. Top that.