Disclaimer: I don't own Sonic
Tails
The young fox stood alone. The mechanical monstrosity standing before him was in fact a very intimidating sight, but he would not back down. This image, this reference to his memories.
The mad scientist piloting this machine glared at him condescendingly. Despite being so young, the kitsune remembered fighting this madman multiple times, as he tried with insane dedication to create a world filled with metallic oppression.
The fox boy remembered when he first met him. His best friend and his brother. He'd never really had any family before. As far back as he could remember, he'd pretty much been an orphan. Maybe he was just an unwanted mutation, a freak of nature that other kids told him he was.
Due to this, spent many a day being teased and picked upon for his uniqueness, not seeing it for how his namesake truly was. On those days he'd often watched the birds flying in the sky, and wished that he could just fly away…
Maybe that's why he followed the blue one. Maybe he felt that he'd be noticed if he was just as fast, brave, and dedicated as he, that people wouldn't view him as some sort of freak.
It paid off. Somehow, he learned how to really fly. He went on many adventures, and learned to have faith in somebody. That someone would be there to help him up should he fall.
But now , in this moment, that friend isn't here now. He realized that it was all upon him. This was the pivotal moment, the time when he'd face his fears, establish his identity, and be the person he wants to be.
"The servers are the seven chaos" Seven Emeralds appeared, one by one, they orbited him, each one's glow becoming more and more brilliant. His fur became spikier, especially on his head.
"Chaos is power, enhanced by my belief..." His fur started glowing, becoming a bright gold, with a matching aura, and four birds, manifestations of his dream to fly, spectral yet shining of the same aura, appeared above him.
"The Controller is the one who believes in the chaos!" Lastly, seven other tails grew out next to his two original ones.
He stood transformed, ready for battle. He was no longer in anybody's shadow. He would not just be a supporter, but would take the front lines. He knew now that he was his own hero.
Author's Note
This was sort of based on Tails fight against Eggman in Sonic Adventure 1. That was his most triumphant development point. I also wanted to "spice up" his super form a bit, so that he didn't just get the birds, so I kinda used the idea of a kitsune with 9 tails as Tails ultimate form.