-I'm not so good at this but imma give it a try-
Twilight walked into one of the empty hallways after one furious day, this whole day was filled with stress and anger with her daughter star shine. There yelling and fussing are always heard every time star acts up, which twilights yells at her about. Discord tries to comfort his wife but she highly rejects it and just runs out of the castle until 3 hours past. As night hit everyone was asleep, except twilight. She was too fed up about today and still had some anger in her, after punching trees and just shooting beams of magic at any object, she just want a break from everything, ever her family and husband. It was time to be alone with no one in HER way. it was time for twilight time. Though, in her time she would be with either galaxy or just reading book in the library. but oh-no-no honey, she wanted to have freedom that she never had before. But how? twilight sighed and trotted to her castle doors, opening one door ajar. Ponies were out in the open, this made twilight think of how to escape without everypony knowing her face, specially her friends and the princesses.
"What am I supposed to do?" Twilight said in complete annoyance. She would be spotted quickly without SOME type of disguise. "Everypony Will ruin my actual free time." twilight thought and thought until she thought of one plan, She had a few magic tricks up her sleeve and know one for this one problem. Transform into something new, to at least SOMETHING. this idea popped right into twilight's head "I got it! I'll transform into someone else!" and with that, twilight's horn started to glow, and glow even brighter every second. When she was just about to change into something new, she said "Please, let this work", and with that, she shot the magic beam right at herself. After some seconds later she coughed due to all the smoke. twilight looked up "Did it work?" twilight said in confusion. She looked in the mirror.......and she was completely different. her coat was no longer purple, it was a some type of grey-blue. her ,mane didn't have her normal hair streaks, instead in was a really dark blue with sparkles at the end. her ears had markings on it, including her eye. her eye was no longer purple, it was a beautiful blue. "W-Woah.......I'm somepony else..." twilight said in complete shock. She looked down a bit and saw a necklace around her neck, The necklace had her exact same colors in it, and it sparkled like diamonds. "well..." She said turning her head directly at the door of her castle 'This is it..." and with that, she burst out of her castle laughing and hopping around in joy.
She ran out and shut the door right behind her, running and jumping around happily. She was free.
"This is the be-" Twilight said until erupted
"hey!" It was Her Big brother, Shining armor. "I'm sorry to be negative towards you, but have you seen a purple alicorn around here? I just want to hang with her." Shining armor said in a sweet voice. "again, sorry bout the weird first met thingy I just want to talk to her."
Twilight did know what to say, since she was somepony else at this one moment. So she tried to tell him the best she could.
"Um, no sir" She said in a calm soothing voice, trying her best to not make it weird. Shining armor sighed in sadness "alright, thanks anyway." He said before trotting off, but suddenly he stopped and turned around to face the mare one more time "and by the way, who re you exactly? And uh, my name is shining armor." Shining said in a so called peaceful voice.
Twilight didn't know what to say, she couldn't just TELL him that's actually her! so she made up a name instead. "U-um.....my name is Rapid Waves." "Rapid Waves" Said in a voice that was shortly funny. Shining looked at her for a few seconds and finally said "Well, Okay! it was nice meeting you, rapid waves!" He said, and finally trotting off into the distance.
"phew that was close" rapid waves said in sighs of relief, and finally spreading her wings and finally flying in the beautiful moonlight sky.
WOOOOO long story is loooong. and I'm not a good one at these so I hope I did okay ^^' So every one meet rapid waves! twilight's secret disguise! she turns into rapid waves when she wants to be alone and by herself and only does this at night. ad this is shining armor's first time meeting rapid waves but doesn't know that's his sister behind all of that blue.
Background credits go to e-49