Prologue
In the Crystal Brighthouse, at nighttime, the mares that lived there were sleeping peacefully on their respective beds. Well, all of them but one, that is.
Sunset Shimmer could not find peace, as she rolled from one side of her bed to the other, as her mind flashed and showed scenes from her most recent adventure, one that could actually send her across the entire multiverse...
"You heard me when I told you lying makes you a terrible friend... And you still lied to me..."
Sunset growled in her dream, as Sonic's words echoed in her mind and reminded her of the events that happened at the Secret Society's HQ.
Flashback
Sonic started to stand up, while the train kept moving upwards.
However, when Sonic looked back at both Boom and Sunset, he did it with a frown, and Sunset's smile faded away after hearing this. "You don't deserve any friends, Sunset. Not if you're gonna lie to them like this..."
Back in the bedroom, Sunset growled and shook her head, as she rolled to the other side and muttered. "No..." In her sleep.
"I've been kicked out of the Society, so if you think I'm here to capture you or Sonic, then you're wrong."
After she said this, Sunny's rage suddenly wiped away, and she stared with wide eyes at Sunset. "...I'm sorry what?" She asked confused, and now that she had calmed down, her friends and boyfriend decided to let her go.
"What you heard!" Sunset replied with a little smile. "I tried to talk FS on testing out if breaking Canon could really threaten the universe... Look where that led me..."
"Listen: I don't forgive you" Sunny started with a frown. "It's gonna take a while before I can say that I trust you... but I will accept your help to stop Opaline and rescue Sonic. After all, we don't have watches like yours..."
"I'll make sure I can amend my mistake, Sunny" Sunset assured with a determinate look. "I don't care if you don't trust me, or if you don't forgive me yet, I will do my best to make sure Sonic's back safe!"
This time, Sunset muttered nothing, she simply limited herself to roll on her place again.
"I... I'm really sorry for not telling you everything. You simply couldn't expect me to say 'Hey, you're a mistake!' and call it a day, though..." Sunset pointed out with an awkward chuckle, before sighing again and looking back and forth between Sonic and Sunny. "I'm sorry for everything. Neither of you deserved all of this crap..."
Sunset looked away from Sonic, already accepting that he probably was going to yell at her in anger... Big was her surprise when Sonic extended his hand to her and smiled. She looked up at him and felt even more surprised when she saw no signs of anger or hate in his eyes.
"I'm not a guy that holds a grudge against anyone, no matter who they are..." Sonic said with joy, surprising Sunset even more. "You screw it up big time... So? Is not like your life has no meaning now that we're on the same side!"
"...Y-You're... forgiving me?!" Sunset asked with wide eyes and disbelief. "B-But why?!"
"You formed this whole-ass operation to get me out of that cage in the HQ, and you even went as far as to warn my friends about FS!" Sonic pointed out with a smile. "I'm still upset you lied to me... But your actions to make up for your mess speak volumes of who you are, Sunset. And in my book? That's a really good start. So, while I cannot forgive you at 100%, I'll say we're in good terms now!"
"Sonic can barely stand––" Tails tried to argue, but Sonic placed a hand on his chest, right over his X scar.
"I appreciate that you guys worry for me," Sonic said with a smile. "But there's a job that has to be done. Like I said back in Eggman's place: if I die, I die. This is bigger than me than any of us."
Sonic then stepped forward and then turned around to face his friends with a determined look. "I know that's been rough, that Opaline has become really powerful, and that everything is scary..." He approached his friends again, placing his hands over Pipp and Tails' shoulders. "But I need you guys to just follow my lead. No time to lose."
Opaline painfully stood on her fours over that rock, looking upwards at the Hyper siblings with rage, but then she noticed that they had combined their energy once more, with Sonic preparing to hit her with a foot, while Sunny was ready to hit the Fire Alicorn with her forelegs.
Opaline tried to launch a fire blast, but Sonic and Sunny's combined attack passed through it, and then, the Hyper siblings hit Opaline, causing a massive explosion of Chaos Energy across the Wasteland.
Sonic and Sunny approached Opaline, who slowly tried to stand up again, just to fail and lay on the ground again. However, as soon as she looked upwards at Sonic and Sunny, she felt more panic than anger.
"S-Sunny! S-Sonic!" Opaline said with wide eyes and an awkward chuckle. "U-Um, perhaps I got a bit too carried away with my new powers and all that stuff. Ah, how about we forget this and just move on while laughing about it, huh?"
"How stupid you think we are to let you walk this off just like that, Opaline?" Sonic asked with anger.
"There isn't a punishment worthy of all you've done!" Sunny added with anger as well.
"Well... I guess this is it, huh?" Sunset sighed.
"Regarding Opaline? Yup, this is thankfully over." Sonic deadpanned, before smirking mockingly. "Regarding me? You wished! I have a dimensional watch now! Don't feel surprised if I suddenly pop up in your universe to catch up!"
"At least sent me a warning." Sunset said with a smile. "My friends have a strange tendency of panic a lot and never let others talk or finish explaining themselves."
"Oh, don't worry. We barely do that, too, sometimes." Sunny confessed with a sheepish smile.
"I wish you luck, Sunset Shimmer." Sonic said with a smile. "Or should I say, Princess Shimmer?"
"Call me like that again, and I'll brake your bones." Sunset replied with a fake smile and a glare.
"You don't like nicknames. Got it." Sonic said with a nervous smile, and that only made Sunset chuckle.
They then approached each other and hugged, while Sunny also joined in eventually. Once they broke the hug, Sunset went with her friends and opened a portal back to her universe. However, before doing so, she looked at Sonic and Sunny one last time, waved her hoof in a goodbye, and then crossed the portal as well.
End of Flashback
Sunset finally opened her eyes, but she did it as if she was just waking up normally instead of feeling any sense of nightmares. She's been dreaming - or rather, remembering on her sleep - all the recent events that put the entire multiverse at stake that happened two weeks ago.
Thanks to said event, she made new friends across the multiverse, and even got a brand new look. She was a bit taller now, as tall as Princess Luna used to be back in the day. She had a larger neck as well, her mane was glowing like Celestia's, and both her mane and tail got a light blue line painted on them.
Yes, her loos was brand new, but her concern remained intact.
Even if that Opaline variant was defeated and the multiverse was safe, Sunset got lots of worries increasing. Who said another variant of another villain from another universe wouldn't do the same? Find a power source that could tear apart realities and allow them to become a multiversal threat?
She immediately shook those thoughts away. She couldn't worry about that right now. And, if something went wrong, she has the watch of the Society. They'll inform if something's not right with the multiverse.
Speaking of said watch, she looked at the nightstand besides her bed. There, she had the watch and the closed necklace where Twilight remained dormant. This fact still broke Sunset's heart, but she knew that there had to be a way to bring her back. She couldn't stay hidden in there forever, right?
She knew she couldn't. She wouldn't let her stay in there. She'll bring her back, no matter what.
The next day, after having breakfast with their friends, Sunny and Sunset decided to walk down the caverns beneath the ruins of Canterlot, with Sunset leading the way while Sunny followed and looked around in awe.
"Wow! I didn't know Canterlot has a restricted section!" Sunny said in excitement.
"Yeah, well, neither did Twilight and I at first before the whole Memory Stone incident, Sunny." Sunset said with a nostalgic smile. "Princess Celestia and Luna kept the most sacred and forbidden magical knowledge and legends from everypony else for safety reasons. Though when Twilight found out, I think she nearly had a heart attack at the many unread books," She said, making them both chuckle a bit.
"Well, knowing her, I believe it's true." Sunny commented, while Sunset gave a sad look, which Sunny noticed, so she placed a hoof over her shoulder. "Hey, don't worry. I'm sure she's watching over us."
"I know, but I still miss her," Sunset said, then she sighed. "I know that she'll always be there for us, but Twilight deserves more than what just happened." She said, looking at her closed necklace, right before they entered the room. "Anyway, we're here." She said, gesturing to the room that was twice as big as the Canterlot Library and even more dusty with cobwebs.
"Oh my gosh!" Sunny exclaimed in awe; "That's more books than the ones on the surface could offer!"
"Yeah, Twilight had the same feeling," Sunset said, then she began to search through the book sections, but when she turned to Sunny, she was standing there in awe at the restricted section, which made Sunset shake her head in amusement. "Just like how Twilight reacted." She muttered to herself. "Hey, Sunny! I know it's amazing, but how about helping me search through these books to find what we came here for!"
Sunny shook her head and blushed sheepishly. "Oh, right! Sorry, got caught up in the moment." She apologized, and then she began to search a section of her own as well. "Are you sure Princess Celestia and Luna had what we need, Sunset?" She asked as she grabbed a book from one of the shelves.
"This place has every detail from the truth of ancient Equestria and forgotten spells and artifacts. Princess Celestia and Luna were pretty thorough when they kept this stuff secret." Sunset said, picking up some more books for her to research, "Though, with this many, we're gonna have to read everything to find it, and Twilight would agree."
"I love researching ancient history!" Sunny cheered excitedly, then she began to read through the books. "Wow! The laws of Ancient Equestria! Mystical artifacts! The true history before Equestria was founded?! Wow, this place does have everything! My Dad would love this place in a heartbeat!"
Sunset chuckled at Sunny's excitement. "True, Sunny. So true."
It's been 5 hours since the two ponies arrived.
Ever since, they've been searching through many sections of books, forming piles or mountain stacks of them around them. Right now, the two tired ponies were reading through some scrolls and books, but if they've been down there for 5 hours, it's clear that they haven't been so lucky.
Sunset never imagined that stopping a tyrant hungry for power from all across the multiverse would be easier than finding a spell between a bunch of books... But here she is.
"Who knew that Chancellor Pudding had tried to pass a law mandating Earth Ponies drinking carrot juice at every meal." Sunny said tiredly, closing a big book.
"I read that one before. It was a weird law, and like Twilight would say, you read the 'fun' books." Sunset said, making them both chuckle. "Some of these I already read, but the other half not so much since Twilight read more of them than me. There's gotta be something in here." She said while searching through a scroll.
"I know, Sunset. But what if there's nothing to open the…" Sunny tried to say, but as she opened another book, she trailed off and gasped in shock. "Sunset! Get over here!"
Sunset flinched a bit, but she rushed with Sunny. "What is it, Sunny? What did you find?" She asked with concern.
"I think I found a way for us to reopen the necklace!" Sunny exclaimed, showing a page to Sunset in the book.
Sunset read through the book, and eventually, she smiled widely. "I knew that there was a way! You found it, Sunny! You found it!" She exclaimed in joy, hugging the Earth Pony, who chuckled from the hug and returned it, before braking it and looking back to the book with a wide smile. "This will be really useful to open up the necklace again!"
"I know, right?!" Sunny asked excitedly, then she stood up. "Now let's take this book back to the Brighthouse and tell the others of what we…" She was cut off when she noticed something else in the book. "Huh?"
"What is it, Sunny?" Sunset asked since she noticed Sunny looking through the page again, and then, Sunny gasped. "What? What's wrong?"
"Sunset, we can do more than just open the necklace again to bring back Twilight..." Sunny said slowly with a wide smile.
"What do you mean?" Sunset asked curiously.
Sunny picks up the book and shows her the page. "We can really restore Twilight to her full form!"
Sunset looked at the page closely before gasping in shock, and then, a wide smile formed on her face. "Sunny! You are brilliant!" She exclaimed, once again hugging Sunny quickly, before looking at the page again, seeing that there were instructions on how to restore a pony's physical form when lost back to its original state. "Hang on Twilight, you are coming home for a real, old friend!" She said to the closed necklace.
"And this time, you'll have a real body!" Sunny cheered as well.
After that, they quickly rushed out of the restricted section, on their way back to the Brighthouse. They have the answers they need not only to open up the necklace and bring back Twilight's spirit but also to restore her body, meaning that the Princess of Friendship/Former Ruler of Equestria will be reborn once again.
End of Prologue