For about three months, the Institute of the Newest Technology has been working and the chief of this institution was a brilliant mare named Source Code. One day she is requested to report to Princess Luna's chamber after her work.
The said mare doesn't expect what's about to happen.

Okay, this is my first story with a non-canon character - it's with my OC named Source Code (she has a dark gray, or blackish fur, blue and teal striped mane and tail, and a breaker ( </> ) cutie mark.
You can find the art of it on Derpibooru (the first art of it was created by my former friend, but he drew this OC being a stallion, so there's a rule 63 tag as well)

Princess Celestia and Luna announced their retirement and Twilight Sparkle to be their successor, and ascend the throne of Equestria. Twilight is stressed about it, but her mind is focused on her former assistant at Ponyville's School of Friendship named Cozy Glow.
She finds her punishment too harsh, therefore she wants to at least try to convince her to be a good pony and release her from Tartarus.

In this story, Cozy Glow wakes up after being thrown into Tartatus, then being brought back by "Grogar" and finally becoming a stone statue with Chrysalis and Tirek...or she thought it happened.
When Twilight Sparkle appears nearby Cozy, a little pegasus is terrified and remorseful, but headmare quickly fills her in on everything that happened during and after the moment Tirek fled Tartarus, almost wiped out all the magic from Equestria and even almost killed Cozy. She also knows from Princess Luna that Cozy had nightmares of being thrown to Tartarus and then turned to stone.
But there are some things Twilight wants to know about Cozy.

In this story, Twilight Sparkle gets out of alternate timelines including war with King Sombra, Changelings and from Equestria under the reign of Nightmare Moon and fights Starlight Glimmer in Cloudsdale.
Starlight gets sick both from changing the past (and their "present") by preventing young Rainbow Dash from doing Sonic Rainboom and throwing Twilight into alternate timelines and decides to eliminate her and Spike once and for all.
But the alicorn outsmarts the former Cult Leader by avoiding her finishing blast and manages to stun, capture and restrain her and finally go back to the original timeline, where it all began.

And Twilight knows exactly what to do with Starlight Glimmer.

- This story is based on Twilight Star's story named "The Personal Royal Body Pillow of Nightmare Moon", which inspired me to write this fanfic.
- To every fan of Twilight Sparkle - small warning: Twilight might seem a bit evil in this fanfic. She is one of my favourite characters in the series though
- To every fan of Starlight Glimmer - She is also one of my favourite characters in the series, this is just fanfic, so chill :D

- This story has tag "fetish" because of containing bondage.

It's been 2 months after Starlight Glimmer and Twilight Sparkle became allies and friends after they fought between each other in multiple alternate timelines.
Now she lives in Ponyville Castle of Friendship with her new teacher - Twilight and Twilight's dragon - Spike.

During one of her friendship lessons with Twilight, she accidentally took Twilight by surprise and confessed love to her, which made Starlight embarassed. One thing she doesn't know is that Princess of Friendship feels the same towards her.
Moreover - she has perfect oppurtunity to show love to Starlight - all her closest friends (including Spike) are now on the trip to Fillydelphia, which means she will be with Starlight alone in the Castle.
Twilight wants to propose to Starlight a private friendship session with her, but not in its form she is teaching her.

This is an alternate take on Season 9 Episodes 24 and 25 "The ending of the End".
Here Cozy Glow feels remorseful for her past actions and wants to redeem herself and make amends with everyone she has hurt. Therefore she...

betrays Lord Tirek and Queen Chrysalis by joining Mane 6 to fight them in "the Ultimate Battle for the fate of Equestria". But her betrayal won't stop the remaining villains nor make them surrender...

They will find another way to defeat Twilight and take over Equestria