The final timeline
"There's no way you can win Twilight!" Starlight shouted, floating above a cloud. She had once again prevented the past Rainbow Dash from doing the sonic rainboom, and once again, her plan had succeeded.
Twilight was exhausted, laying on a cloud, with Spike resting on top of her. "Please Starlight! You have to stop this!" Twilight shouted with what little breath she had in her. Starlight replied with a harsh laugh, as the time hole once again appeared above both Twilight and Spike. "Please Starlight, jus-"
Twilight's words were cut off as she was sucked into the portal, returning her and Spike to the present. "Sorry," Starlight giggled, "I didn't quite catch that," she said as the portal closed.
Starlight rested herself down on the Cloudsdale road, taking a breath to regain her energy. "Hmm, that makes what, six times she's tried to stop me now? Or was it seven?" she asked herself with a smile. That smile however, quickly faded, "Although, if she keeps coming back, she might win eventually... No I can't have that."
Starlight pondered for a moment, thinking of just how determined Twilight was to stop her, it was possible that she might actually win if she keeps trying, so what could she do? "Of course..." Starlight grinned, "Come on Twilight, I'm waiting."
After a few minutes, the time portal appeared above Starlight, sucking her in. "Took your time, eh princess?" After she was sucked in, she was spat back out of the portal again mere moments ago, the same time it always was when they came throught the portal.
When Twilight returned, she immediately put up a magic shield to stop Starlight's first attack. But it never came. Instead, there was a flash of light behind Twilight, and when she turned around, she saw Starlight had teleported Spike into her hooves.
"Hey Spike, mind if I borrow this?" She asked, removing Spike's backpack.
"Wha-"
"Thanks," she said dryly, throwing Spike back over to Twilight. "Now I've got what I want." Starlight pulled out the time scroll from Spike's backpack.
"What are you doing Starlight?" Twilight asked.
"Doing what I should've done a while ago, it would have saved us both a lot of trouble." Starlight replied, grinning victoriously at Twilight.
"No... NO WAIT, STOP STARLIGHT!" Twilight yelled, "YOU DON'T KNOW WHAT YOU'RE DOING!! YOU'RE DESTROYING ALL OF EQUESTRIA!!!"
"Pfft. Oh I know exactly what I'm doing," Starlight replied, "I'm making it so you can't come back her ever AGAIN!!" The time scroll that was floating in front of Starlight immediately burst into flames.
"The... The scroll..." Twilight muttered as she froze on the spot, and all semblance of motivation left her eyes.
"Now just one more thing," Starlight said, shooting a beam of magic at the flying Rainbow Dash, hitting her wing, slowing her down, and stopping the sonic rainboom once again.
She looked back over at Twilight and Spike, who both sat there with pain and sorrow in their eyes. "What, nothing else to say?" Starlight asked as the time portal opened up above Twilight and Spike, and began to lift them both off the ground. "Well then, bye-bye Twilight, and I guess I won't be seeing you again, will I?" she mocked with a laugh.
Spike and Twilight held each other close as they were lifted closer to the portal. "Twilight..." Spike muttered.
"I know Spike," Twilight replied as tears began to fall from both of their eyes.
Both Starlight and Twilight's horn glowed, and Starlight felt herself being dragged closer to the portal. "H-Hey, What are you doing?" Starlight asked as she was pulled into the portal with Twilight and Spike.
"You're coming with us..." Spike replied dryly, as the portal closed.
The portal opened and dropped the three of them on the map, back in the present day. Starlight shook off the impact rather quickly, and laughed. "Ha, now you're stuck without your precious friends, and there's no way you... can..." Starlight looked at her surroundings, or lack there of, "...Stop... me..." The three of them were in some kind of barren wasteland, with no sign of life anywhere.
The three of them climbed down off of the map, onto the sand below. "We know..." Spike replied, hugging Twilight tightly.
"You win Starlight..." Twilight continued.
"Where are we?" Twilight and Spike sat there, both motionless, holding one another tightly. "Tell me!" Starlight demanded. No response. Starlight looked around the wasteland again. "What have you done Sparkle!?"
"Me?" Twilight replied weakly, "What have I done? You're the one who changed the past, Starlight?"
"Oh COME ON!" Starlight replied harshly, "You expect me to believe that without your friends, all of Equestria would be a barren wasteland?" she asked.
"Even if I told you that, you wouldn't believe me, would you? But the proof is all around you anyway, Starlight," Twilight replied weakly, "Just take a look at what you've done."
"T-This is just... a spell you cast to make everything look like this. Yeah, you're trying to get to me, and it isn't going to work!!!" Starlight closed her eyes, and a large wave on energy came out of her horn, covering the land. "There, no more magic sp-" she opened her eyes, and saw that the world hadn't changed. It was still an empty, abandoned wasteland.
"What was that?" Spike asked, to no reply.
"How did you..?" Starlight shook her head, "No matter, I'll just..." She cast the spell again, but to no avail, the land refused to change. "How are you doing this?" she asked hastly.
"Doing what?" Twilight asked.
"Th-This mirage spell, that wave should've cancelled out all the magic in its path, but I couldn't even feel you fighting against me, let alone being able to resist my magic!" Starlight answered, "So how are you keeping this spell up?"
"This isn't a spell Starlight, you're in the present," Spike said, "The present you created."
"That's not possible!"
"Spike and I have seen many different timelines now, each one, worse than the last." Twilight began, "But, the last timeline we went to was just like this one." Twilight wrapped her wings around Spike, "A barren, lifeless wasteland." Twilight lifted her gaze from the sandy ground below, and looked at Starlight, "You know what that means?" Starlight felt her hooves shake, as the realization was sinking in. "It means it doesn't get worse than this."
Twilight then looked straight into Starlight's eyes, and saw that she was finally beginning to understand. "I hope this is what you wanted, Starlight. Because without the scroll, well, you said it yourself. There's no way to go back..."
As for what Starlight saw in Twilight's eyes, there was nothing. The princess had been broken, her spirit was gone, she had no fight left in her. She... she wasn't doing this. With that in her mind, Starlight took one more look at the land around her.
"Do you get it now?" Spike asked.
Starlight was silent, she just couldn't seem to bring herself to say anything, all she did was sit down on the ground below, as tears began to fall. I did this? she thought.
"Hey Spike," Twilight began.
"Yeah?"
"Ready to go?" she asked.
"Go? Go where?" Starlight asked.
"Give me a moment..." Spike replied.
"Where are you going?" Starlight asked desperately, "I swear if this is some kind of sick joke, then you two are dead!!!"
Spike took a deep breath. "Alright," he nodded his head, "I'm ready Twi."
Twilight and Spike broke their hug, and both turned away from Starlight, "Where are you two going? ANSWER ME!!"
"We don't know," Twilight replied, as her and Spike began to walk away, "There's gotta be life somewhere around here, right?" she asked weakly.
"And without that scroll, there's no point in hanging around that," Spike continued, pointing at the map behind Starlight.
Did I really cause this? Starlight thought, Is this really what Equestria is like without her friends?
Spike climbed atop Twilight, who looked back at Starlight one last time. "I hope you're happy with this world Starlight, because it's the one you were fighting so hard for," she said dryly before both her and Spike slowly took off into the sky.
Starlight felt something break apart behind her, and when she turned around, she saw the stone map of Equestria had crumbled into a simple pile of rocks. She took one final look at the dead, empty world around her, as Twilight's final words rang through her head over, and over again.
I hope you're happy with this world Starlight, because it's the one you were fighting so hard for.