Chaos: Tales of Green Hill

The Knuckles Arc (Summary)

Sonic is just this teenage boy, he's seen as a cool guy, best kid on track team, and all around a nice guy. He's friends with Amy, and is all around a pretty popular guy, even if he only talks to a few people.
(Side note, Sonic's technically homeless, he lives in a treehouse in Tails' backyard.)

One day, while biking to school with Tails, he heard something call his name, and accidentally falls off the biking path and down a hill, and he saw something shining in a pile of rocks. He rummages through the stones, and he discovers a green emerald that's about the size of his hand. Tails checks to see if Sonic is okay, since Sonic wiped out, and is surprised when he sees the Emerald. He's shocked that such a nice emerald was just sitting in a pile of rocks. Sonic feels drawn to the Emerald, wondering how lucky he was that this happened. Tails notices the time, and quickly urges Sonic to get his bike back on the path because School will start soon. Sonic quickly shoves the Emerald in his bag, and tells Tails that he'll get the bike after school, as it'd take too much time to get back on the path, and he'll just run to school. Tails agrees and they both go on their way, Sonic to the highschool, and Tails to the middle School.
During his classes, Sonic is too preoccupied with thinking about the Emerald to focus on his schoolwork that day.
After school, Tails goes to the robotics club, and Sonic goes back to where he fell off his bike to retrieve it. As he approaches the scene, he hears a soft voice that makes his hair stand on end, along the sound of the trees rustling in the breeze, and approached his bike. He picked it up, and dragged it up the rather steep slope. As he got his bicycle back on the path, he heard anl near rustling in the brush below. He looked back, and saw nothing. He shrugged, and assumed it had just been a rabbit or some other animal.

Sonic goes into Tails' backyard, and pulls out the Emerald. He observes it closely, taking in how it glimmered in the daylight. The wind picked up, and he heard the soft voice again. He's barely able to make out what it says as he listens closely, but he repeats what he had heard. "For the safety of Earth, Chaos is mine to control." As he speaks the final word, the emerald lifts out of his hands, and his feet cease contact with the ground as he gets elevated a few inches into the air. He feels the wind brush through his hair, and his jacket flutters in the wind. As he regains contact with the ground, he looks at a window of Tails' house, and sees his own reflection. Light golden hair that stood up and piercing red eyes. He gasped at the change in his appearance, and stared in awe for a few moments, before laughing in surprise, seeing how he looked like a Super Saiyan. He looks back at the Emerald, and gives a curious smile, wondering if he's dreaming, or of he really just got an anime like power up from a random Emerald he found.
Sonic quickly grabs his phone to call Tails, but he's forwarded to voicemail. He calls again. Voicemail. He sends Tails a couple texts and takes a picture, just in case it's a one time thing. He slips his phone back into his bag, and decides to see if he has any power ups, or if the transformation is purely cosmetic.
He feels quicker, stronger, and more agile as he plays around with his new form, before he gets a call from Tails, and he transforms as he focuses on picking up the phone.

Tails asks Sonic about what happened, and what he needed. Sonic urges Tails to come back as soon as possible, and he says he'll try to rush back, and Sonic says thats fine. They hang up the phone, and Sonic realizes he's detransformed, and attempts to replicate the transformation, trying to recite the incantation, but struggling to remember the exact words.
Tails arrives, and parks his bike before going to meet Sonic. Tails asks what happened, and Sonic says that this is really cool, and hypes it up before reciting the incantation, and transformation into his super form. Tails is completely stunned by the transformation, and takes a few seconds to reply, before going wild with questions, and saying he looked like a super Saiyan, and saying it should be called Super Sonic as a joke. Sonic likes calling it super Sonic so he rolls with it, and he shows Tails about how he's stronger now. Tails already though Sonic was super strong prior, considering how Tails is kind of weak.