It has been 4 years since the defeat of Nightmare Moon and Luna and Celestia are now ruling together peacefully in Equestria. Celestia would always have her royal guards do her chores while she sat on her throne overlooking her kingdom, at times going out to the balcony to enjoy the scenery. Luna on the other hand, would stay in her room almost all day, only going out to practice magic spells. She would have her meals delivered to her by the guards. Nobody knew what she was doing inside. Rumours started spreading that she was trying to be evil again, but of course nobody could confirm it, Luna wouldn't even let anyone else in her room.

  Weeks passed and one day Luna felt a strong pulse in her chest, and it wasn't her heart. She knew it had to be the Element of Darkness in her. Ever since she was defeated she never felt the Element of Darkness grow active, but now it was slowly beating like a second heart in her. She immediately rushed to her sister Celestia's throne chamber. She wanted to ask what was going on with the Element in her. Why was it growing active again..?

  She slammed open the doors in a hurry and the guards only just had time to jump aside or have a door slam right into their faces. "Sister! Sister! There's something wrong happening, I..." she trailed off as she couldn't believe what she saw. Luna looked all around her, it looked nothing like the throne chamber. The room was now a deep orange, with red sun decorations painted on the ceiling and walls. Even her royal guards didn't look so...royal anymore. Their golden armour was now crimson-orange and their blue mane was a deep red. Some even had a red cape with a sun that looked like Celestia's cutie mark on it. The guards were all holding weapons: Swords, daggers, bows,etc. Luna was starting to feel scared. Celestia was busy hanging a banner overhead and had her back towards Luna.

  "Sister Celestia! What's going on? What is this?!" Luna could feel the Element pulse stronger and faster in her chest. Celestia turned her head towards Luna.

-thump-thump-...

  "Hello Luna..."

-thump-thump-thump-...

  "I see you've noticed the slight changes I made to this place."

-thump-thump-thump-thump-thump...

  "How do you like it? I for one like the banners. I made it myself, you know." It was then that Luna saw the banners hanging from the pillars and ceiling. They had the picture of Celestia's cutie mark on it on a orangey-red background. At the bottom of it were three big words. It read: The Solar Empire.

  Luna was confused. "Solar Empire...? What?" Celestia just gave a short laugh and then flew to Luna so that she was face to face with her. "Join me, Luna. Join the Solar Empire. Together we can take over Equestria!" Luna was shocked. What was her sister thinking?? And aren't they already ruling Equestria? "Celestia, I don't understand..."

Celestia snickered. "Of course, my sister, of course. But join me, and you'll soon understand that ruling in peace can be quite...boring at times. And especially when ruling in peace meant that ponies have their...freedom. They should all be serving me, the way I want them to!" Celestia grinned almost ear to ear.

  Luna didn't know what to do. She had never seen her sister this way before. She especially have never seen her sister so arrogant in being a ruler. Celestia was growing evil.

  She could already feel the Element in her beating wildly, as though it was gonna explode in her chest. The Element of Darkness was begging to join Celestia. Luna wondered if the Element of Light in her was already dead and gone...

She knew Celestia was dead serious in giving her no choice about joining her tyranny in the name of the Solar Empire. She was either with her or against her. Celestia was still waiting for her sister to answer her, and she was getting impatient, the look on her face getting sterner. Luna thought hard about her decision, and she finally made her choice.