At first when I saw this I felt for Dash. Being the only one in the class that failed but the link was a nice touch. It's upsetting when you lose something but it's even worse when it's a dream you've chased your whole life. Still thats what friends are there for. To pick you up when you stumble and to be with you to share in the victory.
Rainbow Dash's failure to pass the exam not only caused her to fail her final exam, but the failure was so catastrophic, it ruined her reputation in the Academy, ruining her only chance at ever becoming a Wonderbolt.
And then Rainbow Dash discovers that her failure was set up by an ambitious rival, yet no one except her friends believed her.
With the Wonderbolt Academy refusing to accept her again, Rainbow Dash, driven by anger and bitterness, forms her own civilian flying team, the Rainbolts, and sought to get her revenge on her rival and the Wonderbolts.
After many years, the Rainbolts come to surpass the Wonderbolts in terms of flying skills and membership. Rainbow Dash meanwhile became a national celebrity of unparalleled popularity.
Her rival, now head of the waning Wonderbolts, tries in a desperate attempt to salvage the Wonderbolt's reputation perform in public an incredibly dangerous and legendary aerial stunt that NOPONY had ever succeeded in achieving since it was first performed (By accident, too, according to inventor's accounts), and which nopony had emerged unscathed.
When the day came, Rainbow Dash's rival goes through the stunt in front of a public crowd, only to fail utterly in the very last, critical moment, which left her wings and spine broken.
And it was at that moment, Rainbow Dash, in the final part of her years-long revenge, shows up immediately afterwards, and in front of everyone, succeeds in performing the legendary stunt, sealing her in the history book.
Rainbow Dash flew high in the air, basking in sunlight and triumph, flanked by her cheering Rainbolts, a huge crowd gone wild showering her with adoration and love. Her crippled rival could only watch helpless anguish as Rainbow Dash took from her EVERYTHING - the place in the history book as the greatest flyer since the legendary pegasi Firefly, the last chance the Wonderbolts to survive and revive their reputation, and above all, her rival's chance of ever flying again.
Rainbow Dash's rival will be left broken and forgotten, while Rainbow Dash would receive the glory that she felt, no, she KNEW, she rightfully deserves.