With Sombra closing in on them, Sonic knew he needed to act fast if he wanted to keep both the empire and equestria safe.
With that in mind, Sonic rushed to Cadence's side before quickly using chaos rejuvenation on her.
Once he was done, Sonic helped Cadence get to her hooves in hopes that she could reactivate the barrier.
Luckily, as soon as she was on her hooves again, Cadence did just that, cutting off the tip of Sombra's horn in the process (said tip was turned into a black crystal that unknowingly to everyone, landed within the barrier).
"That was way too close!" Sonic said with a relived sigh.
"I'll say." Cadence agreed, but was about to lose her balance again before Shining Armor caught her.
"Didn't you just replenish Cadence's strength?!" Shining Armor asked Sonic.
"I did, but I couldn't do it too much." Sonic answered.
"Why?" Twilight asked.
"Cadence is tired, I would only disoriented her if I replenished her completely." Sonic explained, "If Cadence was hurt, I could of done so, but since she isn't, there is a chance the sudden recharge would cause Cadence to be unable to use her magic, and I doubt I could make a chaos shield big enough to surround an entire empire. Also, how would you feel if you were fast-asleep but was suddenly snapped awake without warning?"
"...I guess you have a point." Twilight said.
"Anyway, I'm going to find the crystal heart, it's our only chance if we plan on saving the empire." Shining Armor said as he began to walk out.
"No, you stay here with Cadance." Twilight said as she stepped in front of Shining Armor, "She needs you, Shining Armor I'll retrieve the crystal heart."
"You mean we'll retrieve the crystal heart, right?" Sonic asked as he walked up to Twilight's side.
"But we need you to tell the girls to keep the faire going." Twilight countered.
"Give me a minute." Sonic said before teleporting away.
A literal minute later, Sonic teleported back.
"Problem solved!" He exclaimed, "Although I had to explain to Rainbow Dash that if the crystal ponies knew Sombra was pretty much at their doorstep, their spirits will be anything but lifted."
"Alright, seeing how you two are ready, I wish the both of you best of luck, and be careful." Shining Armor said.
"Don't worry Shining, we'll have the crystal heart back before you know it!" Sonic said before he, and Twilight exited the balcony.
"Are you guys sure it's in the castle?" Spike asked as he, Sonic, and Twilight entered the throne room.
"King Sombra would've been counting on the fact that nopony would dare come looking for it here. They'd have been too afraid to even try." Twilight responded, "And I appreciate the help guys, but I'm sure I can take it from here."
"No way Twilight, there is still a lot more we can do to help you save the empire." Sonic spoke up, "Besides, when we do find the crystal heart, you can be the one who will grab and it and take it to the faire before any of the crystal ponies can notice."
"I guess you have a point." Twilight said before stopping in front of the throne.
"Why did we stop?" Spike asked.
Twilight didn't respond. When Sonic and Spike looked at her, they saw that she appeared to be in deep thought.
This continued for a moment until Twilight suddenly exclaimed, "Of course!"
"Did you find it?" Spike asked.
"No. Because this isn't King Sombra's castle." Twilight responded as she gestured around themselves.
"What do you mean by...?" Sonic asked before he suddenly understood what Twilight meant.
Knowing Sonic was on the same page, Twilight concentrated before her eyes created a the same dark aura Sombra had in his eyes before suddenly firing a beam of dark magic at the crystal the was behind the throne.
Once the dark beam made contact, a shadow moved down the throne before revealing a downward spiral staircase in the middle of the room.
"Whoa, how did you do that Twilight!?" Spike asked in amazement.
"It's a little something Princess Celestia taught me." Twilight responded.
"Good work Twilight, but we really need to get going if we plan on finding the heart before Cadence's magic runs out." Sonic said.
"Right, let's go." Twilight said before she, Sonic, and Spike make their way down the steps.
"So many stairs!" Spike groaned after what felt like forever of walking down stairs.
And there was still so much more stairs left.
Sonic had also gotten tired of walking down the stairs but he quickly thought of a solution.
"I think I got an idea on how to get to the bottom much faster." Sonic said, "But I don't think you guys will like it."
"At this rate, I'll go with anything." Twilight said.
"If you insist." Sonic said before jumping of the edge of the stairs.
"SONIC!!!" Twilight and Spike exclaimed they came up to the edge to see if he was fine.
About a second later, the duo noticed a flash lit up behind themselves and when they turned around, they saw an unscratched Sonic.
"Don't scare us like that!" Twilight yelled.
"Hey! At least I can use chaos control to teleport us to the bottom." Sonic calmly said as he placed his hands on Twilight and Spike before doing just that.
Once the trio reached the bottom, they noticed a single door that was in front of them.
Twilight approached the door in hopes that the heart was on the other side, but when she tried to open it, the door suddenly moved to the other side of the room.
This process was repeated several times until Twilight slammed into the wall when she attempted to charge at the door.
Becoming frustrated, Twilight shot a beam of dark magic at the door, causing it stop, and slowly open.
While unnoticed by Twilight, the door had shot a beam of dark magic back at her, causing the whites of Twilight's eyes to become green.
Sonic and Spike were about to check Twilight to if she was okay, until they heard her speak up.
"Guys! I think found it!" Twilight exclaimed happily before she looked around in confusion, "Huh?"
After a slight pause Twilight spoke up, "I don't know! I opened the door and–"
Twilight paused again before suddenly asked "Good where!?"
"Who is Twilight talking to?" Spike whispered to Sonic.
"I don't know, but I'm putting a stop to it." Sonic replied as he began to walk up to Twilight
"I don't understand! The test?" Twilight continued before pausing yet again before she began to tear up.
Having enough, Sonic grabbed Twilight's shoulders and began to shake her lightly.
"Twilight! Twilight! Snap out of it!" Sonic said as he continued to lightly shake her.
After a few moments of doing this, Twilight closed her eyes before shaking her head. When she open her eyes again, they were normal again.
"Uuhhh, what happened?" Twilight groaned.
"You were hit by some sort of beam that came from the door, and-" Spike explained as he approached the door, only to be hit by a beam of dark magic like Twilight was when the door opened, causing the whites of his eyes to turn green.
"Ponyville!?" Spike suddenly exclaimed in confusion, "How did I get- No! I don't wanna go! Please, Sonic, Twilight, don't make me!"
Not wanting this to escalate, Sonic walked up to Spike before grabbing his shoulders and began to lightly shake him like he did to Twilight until he finally snapped out of it, causing the door to slam shut afterwards.
"King Sombra's dark magic." Twilight said, "It's a doorway that leads to your worst fear."
"So that's what happened." Sonic said before turning to Spike, "You okay little bro?"
"We were home. You both told me you didn't want me anymore. You were sending me away..." Spike began to explain before finding himself in a hug by both Sonic and Twilight.
"We would never do that to you Spike." Twilight said.
"I would rather loss both my speed and the chaos emeralds than turn my back on my little brother." Sonic said.
After a moment, Spike hugged the duo back, "Thanks guys."
"No problem little bro." Sonic said before he and Twilight ended the embrace.
As Twilight was about to undo the enchantment on the door, she noticed Sonic was approaching the door. Acting quickly, she grabbed Sonic's wrist with her magic.
"Sonic, what are you doing?" Twilight asked.
"That door shows someone their greatest fear right?" Sonic asked, "We'll, I'm curious as to what it would show me."
"We don't have time for this Sonic." Twilight reminded him.
"I know, but this is basically a once in a lifetime opportunity, and I kinda want to take advantage of it." Sonic said back.
After thinking about it for a moment, Twilight let go of his wrist before saying, "Try to make it quick."
"Will do." Sonic said as he approached the door.
Once he was close enough, the door opened and shot him with a beam of dark magic, causing the whites of his eyes to turn green like it did for Twilight and Spike.
After a moment, Sonic began to look around in what appeared to be shock.
"What the!? What happened to ponyville!?!" Sonic suddenly exclaimed.
Sonic then began turning his head around until it appeared something caught his eye.
"Spike! girls!" Sonic exclaimed.
After a moment, Sonic said, "Guys, are you alright? ...Come on guys, get up!"
Sonic then turned his head before gaining a more worried expression, "...Aunt Luna? Shining Armor? Cadence? ...Come on, get up please."
Sonic turned his head again before freezing in place.
Before Twilight and Spike could question him, they saw tears form in Sonic's eyes.
"No! No! No! No! No! No! No! NO!!! PLEASE!! OUT OF EVERYONE, WHY DID IT HAVE TO BE YOU?!?" Sonic exclaimed as he fell to his knees while seemingly trying to shake someone, tears pouring out of his eyes.
"Mom!" Sonic muttered out, causing Twilight and Spike to grow even more worried.
"No! No!" Sonic Weeped before suddenly turning to his dark form.
"NNOOOOOOOOOOOOO!!!!!" Sonic yelled as his dark aura extended about a foot away from his body, tears still in his eyes.
Knowing Sonic had enough, Twilight and Spike ran to him before wrapping him in a hug.
"Sonic! Snap out of it!" Twilight exclaimed as she and Spike began to shake him, "It's not real! Everything is going to be okay!"
This seemed to have reached Sonic as his dark aura began to weaken before Sonic returned to his normal self.
"What did you see?" Spike asked.
"...I'd rather not tell." Sonic said as he slipped out of the duo's embrace, "But we should get going, if we plan on stopping Sombra."
Not wanting to argue after sew what Sonic experienced, Twilight walked up to the door before firing a beam of magic at the door, causing it to open, only this time, it revealed a room full of blue crystals.
When the trio stepped through, they let out an annoyed groan when they saw more stairs that led upwards, which also seemed like it was endless.
"We don't have time for this!" Sonic said as he grabbed Twilight and Spike, "Hold on tight!"
Nodding in understanding, Twilight and Spike held on tight as Sonic sped to the top of the stairs.
Once they reached the top, the trio saw the crystal heart levitating above a wide circular disc.
"There it is!" Twilight exclaimed happily as she ran towards it.
As soon as she did that however, the disc began to lightly up, causing Twilight to knock it towards Sonic and Spike.
A literal second after, black crystals suddenly sprouted around the disc, Trapping Twilight inside.
"Twilight!" Sonic and Spike exclaimed as they ran to the crystals.
"Don't worry, I'll teleport myself out!" Twilight called out before doing just that, only to be teleported back inside.
Twilight repeated this several times before finding that it was pointless.
"Guys, grab the crystal heart and get it to Cadence!" Twilight said.
"But Twilight, what about the test?" Spike asked.
"King Sombra is already attacking the Empire. He could reach the Crystal Ponies at any moment!" Twilight countered, "Just get the heart and go!"
"But-" Spike began before being by Sonic along with the crystal heart.
"Twilight has done all she could do Spike, it's time to finish this for her." Sonic said, "Don't worry Twilight, we'll come back for you as soon as give Cadence the heart!"
With that, Sonic jumps out of a nearby window with Spike and the crystal heart in tow just as more black crystals formed behind them.
At that point the duo saw that the barrier had finally gone down, allowing Sombra to finally enter the empire.
"Looks like Cadence finally ran out of magic." Sonic said he set Spike down as while giving him the crystal heart.
Before he could ask why they stopped, Spike was blinded by a yellow flash. When the light died down, Spike saw Super Sonic, who had a determined look on his face.
"Time to show Sombra that he isn't welcomed here anymore!" Super Sonic exclaimed.
Spike nodded in agreement but before he could hope onto Super Sonic's back, a black crystal formed underneath him, causing him to fall and let go of the crystal heart.
"Spike!" Super Sonic exclaimed before diving to save him, and to recover the crystal heart.
It was at that point King Sombra had appeared far beneath the duo and had began to make his way towards the crystal heart thanks to the help of his black crystals.
Knowing that it was do-or-die at this point, Super Sonic increased his speed as Sombra did the same.
Just as it seemed as both the heart Spike was in either Super Sonic's or Sombra's grasp, a pink blur appeared and swiped both Spike and the crystal heart.
When Super Sonic turned towards the pink blur, he saw that it was Cadence who had come to the rescue.
Knowing that Sombra was finished, Super Sonic activate chaos control to prevent the dark king from interfering.
Once Cadence got the crystal heart to the base of the castle, she then announced, "The Crystal Heart has returned. Use the light and love within you to ensure that King Sombra does not."
With that, the crystal ponies one by one began to bow, causing a blue light to form underneath them and spread.
Once the light reached the crystal heart, the crystal unleashed a large wave of magic throughout the empire.
When the wave reached Sombra (who had recovered from the chaos control), he let out a scream before he and all of his black crystals where blasted out of existence.
Once the wave reached the top of the castle, said castle released a large burst that spreaded across equestria.
After everything settled down, Super Sonic, Spike, the mane six, and the royal couple saw that the crystal ponies (and themselves) where now sparkling like diamonds.
Once Super Sonic retrieved Twilight from the tower, he decided to be funny by saying, "Looks Twilight isn't the only one to sparkle anymore."
This caused Twilight to playfully roll her eyes while everyone else let out a small laugh.
A few hours later, Sonic and Twilight where in canterlot castle as they explained the events that took place in the crystal empire and how it was Sonic and Spike who ultimately saved the empire.
Luckily Princess Celestia said that by choosing to stay in the prison to save time, she put the safety of the Crystal Ponies before her own future. She then explains that she would rather have a student who understands self-sacrifice than one who puts her self interests first.
Knowing what that meant, the duo let out a cheer before they begin to make their way out of the throne room.
But before they could leave, Princess Celestia stopped them.
"Sonic, there has been something I've been wanting to talk to you about for a while now." Princess Celestia spoke up.
"What is it mom?" Sonic asked before he and Twilight stopped.
"After much demand from several nobles and subjects alike, I have decided to have a festival dedicated to you." Princess Celestia said.
"What? Why?" Sonic asked, having been taken completely off guard.
"They argued that since you have saved equestria several times already, they wanted to have a way to have you remembered for doing so, and it was decided having a festival in your name." Princess Celestia explained, "They also demanded it because there were already something similar for me, Luna, and Cadence."
"Those being?" Sonic asked.
"The Summer Sun Celebration for me, Nightmare Night for Luna, and I guess Hearts-and-Hooves Day for Cadence." Princess Celestia responded.
"...Okay I guess that's a decent point, but I had help during all those times." Sonic countered, "I can't just take credit for something didn't do alone."
"I understand that Sonic, I even explained that to them as well, but they wouldn't change their minds." Princess Celestia explained.
Sonic was about to counter when Twilight spoke up, "It's okay Sonic, I understand that the public can be a bit blind at times, but wouldn't put it against you. And I'm sure the girls would understand as well."
Sonic had processed this for a moment before saying, "Okay, I'll accept it, but only if you explain to everyone how exactly I helped save equestria all those times."
Hearing this made princess Celestia smile, "I'll do my best to make that happen. Now, we need to think of a name for the festival and when that will take place."
"That I know for certain will take a while..." Sonic said.
"...which brings us up to now." Sonic said as he and Twilight had finished explaining to Spike and the rest of the girls as they rode in the friendship express back to ponyville.
"I still find it awesome how you will be having a festival dedicated for yourself, Sonic." Rainbow Dash said.
"Yeah! It's gonna be super duper!' Pinkie exclaimed happily.
"So how do y'all want us to help out?" Applejack asked.
"For right now, only possible names, and when it should take place during the year." Twilight responded.
"Maybe we should worry about when it should be held later." Spike spoke up, "It could take weeks to think of a perfect time for it to be held considering we don't want to have it take place at the same time with some other special holiday of some sort."
"Spike has a point there." Sonic said, "Now, what could be a good name?"
The group had thought about it for a moment before Pinkie spoke up, "How about Sonic Mania?"
"Sonic Mania?" Applejack asked.
"Why not? It has a bit of a ring to it." Pinkie said.
"Sonic Mania, huh? It's perfect." Sonic said, "I'll be sure to tell my mom that'll be the official name."
"Now that we have a name for the festival, what should we do now?" Spike asked.
"Nothing really." Sonic said as he sat back with his arms behind his head, "Just sit back until further updates on the festival, or until something unexpected happens."
"With everything that's happened so far, I'm sure that's something we all can count on." Twilight said before she and the rest of the group let out a chuckle.