Celestia was on her knees.
The Alicorn was running from her, a steady beat around him as an aura, boosting his magic.
"THIS IS FOR ALL THE ALICORNS YOU KILLED!!" and sound deafened her. Pure sound. Pure noise.
Too much was happening. Celestia was losing this fight. She couldn't lose this. She just couldn't. "ENOUGH OF THIS FOOLISHNESS. GO TO WHERE YOU BELONG." Her horn glowed, but the older Alicorn struck first, sealing the use of her wings. A smoother, heavy beat literally surrounded him, playing loud enough for the entire castle to hear. "I won't let you seal me. Never. You keep thinking you can stay in power. They'll see through your masks soon enough. Even if you seal me off, I AM SOUND. I AM THE NOISE EVERYONE HEARS. I AM CONTROL. I AM DESTRUCTION AMD ORDER. I AM TRUE SOUND. MY NAME IS AURAAA!!"
He struck her with knives of noise, and his horn was glowing, and moved as he switched and edited sound in his mind. This was truly him. He blinked, and his eyes glowed white as soon as he opened them again. "Your time has come, Celestia. Goodbye." His horn became white at the tip, and the beat he made was pulsing in a 10-meter range. Then Luna came in. A young filly Luna. And she screamed as loud as she could. Even Aura heard it with power over sound, and for that matter, blocking it out. "Don't hurt my sister...please..." Luna broke down then and there, bawling. Aura stopped, the beat changing, and he stopped flying to embrace her. "Celly's been bad...we need to show her that, okay? I'm gonna take her away from the castle for a time-out, okay?"
And Luna kept crying. "Celestia. Look what you're doing to your sister. This is enough. Give in."
Celestia stood, weakly, afraid she would topple any second. Her horn powered up, and she fired its subtle magical blast. Aura became trapped, but his drum beat continued on. He wouldn't give in. "Sorry, but my rule lives on. 'I Name You Sound and Noise. You Shall Be Cast Away and into Your true Realm: that of the Dreamer's.' BEGONE!"
Aura's beat became him, and he became it. The magic bordered his sound aura and blinked him away in a pony-sized orb of light. Celestia looked back down at her crying sister, unsympathetic. "Luna. Liste-"
"YOU SENT AURA AWAY TOO! LEAVE ME ALONE!" and Luna flew away as fast as she could. Celestia wondered about herself and her morals, as well as motives to hide away the other Alicorns from the world. Control...it came with price. They cost her. But...she didn't want her sister gone. She would be the last one, then...the pain was- "No. Not right now, Tia. Don't think about it."
Aura didn't exactly awaken, but saw everything like normal. He looked around, but couldn't see anypony- "Hi!" Aura didn't know what the voice came from, but followed the vibration of sound in the air.