In the second demension version of Equestria, once a well respected and loved pony, Twilight Sparkle made herself known to be quite a hero, as well as her friends. But one day when the spirit of disharmony, Discord, returned to Equestria. The Mane 6 were to use the Elements of Harmony to defeat Discord, but Discord was able to foil them and break them up as friends forever, by tricking them into becoming polar opposites of themselves; all but Twilight of course, until all her friends give up on her and she loses all hope. In the original version, Twilight over comes the setback when she goes back to the Library and recieves messages from Princess Celestia. This version of Twilight didn't go back to her home when all of her friends walked away from her, her choice instead was to go to Discord and ally up with him, and this decision changed the outcome of her demension forever...
After Twilight and Discord teamed up to cause chaos together across Equestria, their mutual crisscross turned into a doublecross. Twilight turned Discord into the Royal Guard, after Twilight found out that Discord was going to turn her into stone when he was done with her. Although he evaded and escaped the Royal Guard several times, Discord was eventually taken down by Celestia, and imprisoned in an orb with no hope of escape. Twilight decided that chaos wasn't enough as she decided to dominate Ponyville and attempt to overthrow Celestia as she worked her way up. She was however, defeated when Spike, her once faithful assistant(but left her when she turned evil) reluctantly helped Celestia knock Twilight down before she used her magic to reach Canterlot.
After Twilight was defeated, she fled Ponyville and became a wanted fugitive, much to Celestia's sadness. Celestia was hoping that she could win back her student, and turn her back to good so she could restore her friends and put the Elements of Harmony back to use. But Twilight wouldn't have any of that, especially after she found new means of power.
One night, she decided to sneak into Canterlot's magic studies to find a spell that would help her rise back to the top. It was a silent evening, which made her mission very tough. She had to be stealthy. There were two guards at the castle door who were a couple of the finest guards in Equestria.
"Do you hear anything?" said the first guard.
"Nope" said the second.
Twilight threw a rock, and made the guards jump.
"Did you hear that?" said the first guard.
"Yeah" said the second guard.
"Go check it out" said the first guard.
"Alright" said guard number two. He walked over to where the sound was coming from and he found a rope tied to a tree. "Who put this... heeeeeeeeeeeeeeeeeeeeere?"
The second guard found himself trapped in one of Twilight's clever traps. "Naaaaaaaaa dang it!"
The first guard, having heard the second guard's noises went to go check out the scene. As he walked closer, he was finally able to see his comrade tied to a tree. His muffled warnings came too late as the first guard suddenly found himself covered with a big brown sack. Twilight used her magic to tie up the bag and tied it to one of the branches on the tree.
"Well, removing those guards was easier than I thought" said Twilight as she made her way into the study room. "My old studying grounds... this brings back memories... Why did I have to go and make friends? They ruined everything! Okay, Twilight focus."
Twilight browsed throught the books and finally found one called "portals". She opened it up and turned to the chapter, "Alternate dimension".
"This is perfect!" said Twilight to herself. She read all that she needed and was on her way out the door, when she bumped into someone on her way out. "Princess Celestia!"
"Twilight Sparkle, please I beg of you again, stop this quest for domination! It's not worth it! I don't want to have to put you behind bars!"
"You don't get it, Celestia!" said Twilight. "I failed so long ago! There's no going back for me. This is how it's supposed to be now, things can never be as they once were. There is nothing for me here, now! I will soon rule another demension and I will be respected at last!"
"What?" said Celestia as Twilight teleported out of the palace and onto the streets of Canterlot. Celestia sent the guards after her.
"Twilight Sparkle, stop in the name of Celestia!" said the lead guard.
Twilight ran and ran as fast as she could. Knocking over barrels and tables to keep the guards from gaining on her. But all her running had finally become futile when she found herself at a dead end in an alley. She turned around and three guards were closing in.
"Ha!" said Twilight. "You really think you can capture me?"
"Don't make things worse for yourself, Twilight!" said the guard. "Please just come quietly and hand over the book!"
"NO!" yelled Twilight as she used the portal spell and disappeared into thin air.
"Dargh!" said the guard. "We lost her!"
Moments later, Twilight found herself in Ponyville of the other dimension, what we the audience would know as the regular dimension. It looked like the old Ponyville of her dimension.
"Nice to see things haven't changed much here" said Twilight(in this dimension, she'd be known as evil Twilight). "It's perfect for the taking!"
Twilight gave an evil grimmace as she gazed at Ponyville, standing by the sign that said "Welcome to Ponyville". She went into the Everfree forest to work on her plan.
"Soon everypony will learn to fear the name, 'Twilight Sparkle'!" she thought to herself as she disappeared into the woods.