It had been a few days since the royal wedding of Cadence and Shining Armor had occurred, the exciting news having spread all throughout Equestria, along with the Changeling invasion thwarted by the newlyweds, the Elements of Harmony, and the heroic stallion and his companions with their key-shaped weapons. In Canterlot's castle, Celestia was busy going through her usual duties as the ruler of the land: dealing with all sorts of paperwork, the nobles that request her audience over pointless accusations or meaningless changes to the city, hiding her annoyance at her millennium long work as a princess. While going through another bill from some stuffy snob from her council, the doors to her throne room burst open as a guard ran in, panting heavily and looking distressed.
"Your highness! Urgent news from the north!" he said. "Scouts from the northern base had reported something that had just recently appeared a few days ago...It has returned."
The alicorn dropped the scroll she was reading in shock, gasping in horror as she knew exactly what her guard meant. "Find Cadence and Shining Armor immediately! Tell them to head where it has reappeared and keep that land safe until then!" The guard saluted and hurried off to find the newlywed couple. Celestia began to panic, dismissing her other guards from the throne room. "This is bad. The kingdom's come back...as well as...him..."
She grabbed a couple blank scrolls, writing out a hasty message for both Twilight and Sora individually. After writing out her urgent, yet brief, news, she called forth a black tome with her magic, a very special spellbook that's seen much age, though still kept in pristine condition. She had plans for this book for Twilight, but with the news of a kingdom she knows of having returned, it seemed too perilous at the moment for her student to look into it. As she was about to send Sora's letter, she heard hooves echo against the floor of the throne room. She looked up with a pained expression on her face, her sister, Luna, approaching her, tears welling up in the blue alicorn's eyes.
"...It has returned, hasn't it?" she asked.
"...Yes," Celestia admitted.
"...And...so has he..." Luna's tears began to fall as memories of someone she had thought to never see again has returned.
Down in Ponyville, out in the empty fields far from the town, Sora and Riku were in the middle of a friendly duel using their Keyblades, the Mane Six, Spike, and Kairi all standing by and watching the two friends fight. The two expert fighters were evenly matched, their blades clashing with less power than they would against a real opponent. They've already gone through a lot of moments where they tried to kill each other, so it was fun for them just to have a normal fight for competition's sake. The match was immediately interrupted as Sora's Keyblade pointed up in the middle of a swing, a scroll from the princess appearing above him and dropping onto his muzzle.
"What the heck was that?" Riku asked, disappointed that their match was interrupted by an odd spell.
"Darn it, Celestia. Now of all times." Sora unfurled the scroll and read it to himself while the others approached the two stallions. "Seems like the princess has something important for me to do."
"Aww man!" Pinkie whined.
"What is it that she wants you to do?" Kairi asked.
"No idea. She wants to me meet up with her in the castle to tell me personally." Sora rolled the scroll back up and stuffed it away in his red pouch. "I'll be back soon."
The teen flew off and headed toward the mountain city, leaving the ponies and baby dragon behind. "I hope it's nothing serious." As they watched Sora leave, Spike suddenly belched out a scroll, the rolled up parchment dropping from his magical fire breath. Twilight grabbed it with her aura and read it, her eyes widening as she began to panic. "Oh my gosh. Princess Celestia's giving me a test! Today! Oh no! I didn't know she was going to give me a surprise test! I need to get ready!"
Twilight ran off into town, dropping the scroll while the others watched her leave. They hurried after her as they arrived at the Golden Oak Library. The lavender unicorn ran around, blindly grabbing random books, parchment, quills, blank flash cards, anything her magic could get as she stuffed them in her saddlebags.
"Oh boy," Kairi muttered. "She's freaking out again."
"Is she really freaking out about a regular test?" Riku asked, Twilight stopping her packing as she slowly turned her head toward the pegasus stallion.
"...A 'regular' test?" she asked, her eye twitching as she was on the verge of blowing up. The others all backed away from Riku as Twilight stomped up to him. "This is more than just a 'regular' test! Princess Celestia, my mentor and Equestria's leader, is giving me a very important test! And I'm not ready for it!"
"It's just a test. Calm down," he said.
"...J-Just a test? JUST A TEST!?" Twilight shouted. "This test may very well spell the future of my studies under her tutelage, and you're telling me to calm down because it's just a test!?"
"Yes." The library was deathly silent, the unicorn leering at the silver-haired stallion as her horn began glowing brightly. "...Uhh, you ok?"
Twilight let out a loud grunt of frustration that could be heard all throughout Ponyville, her magical blast causing the entire library to leap out of its roots several yards into the air. As soon as the large tree building fell back down, the inside was a mess, the others slightly shaken by the impact while Riku's body had been shot into the wall of the tree.
"...Well, I think she took that well," Applejack commented as Riku groaned in pain, slowly slipping out of the pegasus-shaped indent he made.
Sora entered the castle as he reached Canterlot, flying past the city over the stuffy nobles walking about down below. Since he was now fully welcomed as an honorable hero by the royal guard instead of being considered skeptical, the Keyblade wielder was able to come and go whenever he pleased. Celestia said she would be waiting for him in the throne room, not hesitating to walk inside to see what urgent news she had to tell him.
As he walked down the long stretch of the room to where Celestia stood next to a newly placed stain glass window, Sora was surprised to see Luna standing next to her as well. The window showed the events of their victory against the Changelings: Shining and Cadence making a heart shape with their bodies, pink barrier formed around them as the many drones that were part of Chrysalis's army were flung by the light emitting from barrier. They seemed to be discussing something before he walked in, though it looked like Luna was greatly distressed about something. Both princesses didn't hear him come in as they argued.
"Luna, I told you several times, you're not going with them," Celestia said sternly. "I didn't want you to know about this, but it's too late for that."
"You know how much he means to me," Luna argued. "Sora was able to save me. He can surely save him too."
"He's not the stallion you once knew anymore. He's long gone. And saving the empire is more important than-" As Celestia turned her head to look at her stubborn sister, noticing Sora standing right next to them. "Sora. You're here."
"Uhh...Should I let you two argue in private, or should I intervene before an alicorn fight happens?" Sora asked, hoping the latter event wouldn't actually happen.
"No. It's fine." Luna leered at Celestia, turning away from her sister with a disgruntled scoff. The white alicorn sadly sighed. "I really don't want to fight with Luna again. Verbal or physical...Anyway, on to the issue we were discussing earlier. Sora, we have an assignment for you, and Riku and Kairi if they are able to assist."
"Of course. If it's a Heartless problem, we can handle it," Sora said with confidence.
"Yes, but...I think it's a lot worse than what you may think." Using her magic, Celestia summoned a bright crystal, shining her golden aura into it. The light reflected off the mineral and created a light holographic image of a magnificent kingdom on the ground before Sora. The teen's eyes shimmered as he stared at the many buildings and the palace in the center gleaming, made entirely out of crystal. "For a thousand years, a kingdom has been lost to Equestria. A kingdom made out of crystal, known as the Crystal Empire, has now returned."
"I kind of would have guessed that just from looking at this place." He reached a hoof out and tried to touch one of the buildings, his limb phasing through the illusional representation of the crystal city.
"The Crystal Empire has powerful magic," Celestia continued. "Luna and I don't know everything that it has, but it was once an important part of Equestria. If love and hope fills the kingdom, it will spread through all of Equestria...However, hatred and fear once took hold of the kingdom by a unicorn tyrant." The city zoomed in onto the palace in the center, though the Crystal Empire seemed to turn a bit grim compared to how it was supposed to be. Standing on the balcony was the tyrant, a dark gray unicorn stallion, his mane black, wearing a red cape with tattered white fur trimming and silver regalia worn to show his royalty. What was disturbing about this demonic looking stallion was his curved red horn, red eyes, and fangs. "This is the stallion who attempted to take over the empire many years ago: Sombra."
"...Yeah. This guy definitely screams 'bad guy'. Just the way he looks and what he's wearing gives it away." Sora's comment angered Luna, dragging the pegasus by his jacket collar through the illusion and hung in the air mere inches from her face.
"He is not evil!" the alicorn shouted. "Don't you dare listen to a single thing my sister says about him!"
"Whoa, hey! What's with the hostility, Luna!?" Sora asked in confusion. "Why are you defending someone who tried to take control of a kingdom?"
"I was about to get to that," Celestia said, gently dragging Sora out of her sister's telekinetic grip and away from the possible thrashing he would have gotten.
"What? Are you going to tell me that your sister had a thing with Sombra?" The room was silent, neither princess giving an answer. It took Sora a moment to realize he had answered his own question, his jaw dropping as he looked at Celestia and Luna with shock. "...Whaaaaaaaaat!? You seriously liked this guy, Luna!?"
"He wasn't like that before we had to..." Luna looked away, her eyes welling with tears.
"...I really don't know much about their relationship, since Luna had tried to keep their love a secret from me," Celestia said, putting the shocked stallion back down to the floor. "We've only been in the Crystal Empire a few times in our lives, and Sombra was indeed a different stallion than what I've shown you. He was born the only unicorn in the empire, though he was not like the other crystal ponies that lived there."
"'Crystal ponies'?" Sora asked. "They're actually made out of crystal?"
"Their magic, filled with love and happiness, give them a crystalline appearance. They were all mainly earth ponies with incredible magical power only native to the empire." Celestia continued showing the events through the crystal that had come from the Crystal Empire, showing all of the crystal ponies held captive under the dark unicorn's rule, all of them in chains as they stepped in line to a section of the city. "We didn't know what had caused him to turn to the dark magic he wields now, but Luna and I managed to stop him before he could attempt to take over the rest of Equestria."
Celestia and Luna both appeared in the crystal's illusion, both alicorns using their combined magical power to stop Sombra. They didn't use the Elements of Harmony, which either meant they either stopped Discord before or after defeating Sombra. Their magic sent the stallion in the shadows as his body shifted to a gaseous form, roaring as he was sent into the shadows he had become. The Crystal Empire disappeared along with him, the dark unicorn having cursed the kingdom to vanish along with him, until now where it has come back, along with the evil king.
After giving the Keyblade wielder everything about the Crystal Empire that they know and what had happened back then, Celestia placed the crystal back near her throne. "So, you two managed to beat him without the Elements of Harmony. But, now he's back, and the Crystal Empire is in trouble...again."
"Sadly, yes," the white alicorn. "I have already sent Cadence and Shining Armor hours ago to help protect the empire, their protection spell strong enough to keep Sombra at bay for a little while."
"Boy. Their honeymoon must have ended earlier than it should, huh?" Sora asked as he brought his forehooves behind his head.
"Sora, I need you and your friends to stop Sombra, and to keep Twilight and her friends from any harm," Celestia said.
"By stop, you mean save, right?" Luna questioned.
"Luna-" The blue alicorn ignored her older sister and stomped up to Sora.
"Sora, your light had freed me from Nightmare Moon and brought me back to normal. That light can destroy darkness and free those who were overwhelmed by its power." Luna placed her forehooves on the pegasus's shoulders, staring at him with pleading eyes. "I don't know why Sombra had gone down this path, but I wish for him to return to the stallion he used to be. Please save him from the darkness..."
Hearing a request like that was really conflicting to Sora. There was a possibility to save someone if their hearts were shrouded with darkness, but depending on how strong their light is, they can easily be taken over if it's too late. Riku's heart was strong enough to fight back against his darkness, Sora had saved the Beast when Xaldin tried to manipulate him into succumbing to his rage, even Twilight was rescued by Kairi after she nearly lost her heart to darkness. But there was a big difference that had taken place between Luna and Sombra after a thousand years of having darkness fester in their hearts: the former had been struck by the Elements of Harmony, artifacts that were basically considered holding the power of light, suppressing her darkness along with her banishment. However, with Sombra, he was banished into the shadows for the same amount of time, a terrible place to be when one uses the power of darkness. It would only make him stronger and his heart would already be lost to darkness, not considered a Heartless, though he might as well be one if he's more powerful than he was in the past.
Sora sighed, seeing the disbelief in Luna's eyes as he was about to give his possible theory. "I'm not sure if I can...but I'll try. It may already be too late."
"What are you talking about?" she asked. "Light defeats darkness! How is it too late!?"
"Both you and Sombra were affected by darkness," Sora began to explain, hoping Luna would understand. "I managed to free you with the help of the Elements of Harmony. Your heart's light was kept away from the darkness for a thousand years until you came back from your banishment. With Sombra...you and Celestia banished him to the shadows. Without the elements' magic. That strengthened his darkness, and it might have already taken full control of his will."
"...N-No..." Luna backed away from the Keyblade wielder, tears streaming down her cheeks at the horrible realization. She shook her head, wishing that what she heard, the serious yet sad expression on Sora's face, was all just a horrible nightmare and it was all a lie, but it was a terrible possibility. "...No...W-What have I...?"
Celestia was just as shocked as her sister, both alicorns having doomed a stallion they had known that was once a normal pony. She tried to comfort Luna, but the lunar princess teleported away, most likely to her room to grieve over her guilt. Sora felt awful, seeing just how much Luna cared about Sombra, but there was no chance of saving someone with a thousand years in darkness.
"...Should I have lied?" Sora asked.
"No," Celestia said. "It would have been worse to hear the news of his demise when claiming you could save him...But, if there's any possible way..."
"If we have to fight him, and if we try to use light...It'll just kill him, just like it would to a Heartless." The teen shook his head in pity, then looked up at Celestia. "We'll save the Crystal Empire. You can count on me."
"I know." Suddenly, the throne room doors opened up as the two looked over to the sudden intruder.
"I'm here! I'm ready for my test!" Twilight ran up to them, sweating profusely as she tried to pull out a dozen study supplies from her saddlebags. She dropped a long piece of parchment, the paper rolling out a couple dozen yards across the room, stopping at Celestia's hooves. "Sorry! Sorry!"
The lavender mare tried to roll the parchment back up, though with her muzzle instead of her magic. Sora and the princess sighed as Twilight was so overly stressed that she forgot she had magic to help organize her unorganized organization. While Celestia rolled up the paper, Sora approached Twilight and lightly tapped his hoof against her head.
"Twilight. Breathe. None of us want you to go all crazy on us again," the pegasus teased.
"Did Celestia give you a test too, Sora?" Twilight asked. "Did she not tell you you had to take a test in your message too!? Wait, when did you become her pupil!? What's going to be on the test!? I don't think I'm ready! Why wasn't I-!?"
Sora quickly shoved a hoof in Twilight's mouth, silencing her stressed out rambling. "Relax, Twi. You'll find out everything you need to know from the princess."
He took his leave to allow Celestia to explain to Twilight what's going on, though her "test" is also going to be the most dangerous she would have to take. Sora navigated his way to the front doors of the castle, accidentally smacking Spike in the face as he paced around the entrance in anxiety.
"Ow...Where was Pinkie when I needed her?" Spike asked the heavens, the stallion helping the baby dragon up on his feet.
"Next time, just stay away from any doors," Sora said. "So, are the others here too? Did Celestia call everyone?"
"As soon as you left, Twilight got a message about a test the princess was going to give her," Spike explained. "The others are waiting down at the station, mostly because Twilight was freaking out over the exam she was going to be taking...Did she pass?"
"I think her test just started...Though we seem to be on a bit of a time crunch." Luckily, Spike didn't hear Sora with his last statement as he sat down on the stairs. "I'll go ahead and meet up with the rest of the gang while you wait for Twilight."
The small dragon nodded as Sora flew up into the sky and headed for the station. Before he reached the train station, his flight took longer than it should have, lost in thought of the new threat that had appeared in Equestria. Even though what he heard from Celestia and what he saw from the crystal, Sombra seemed far more dangerous after a thousand years trapped in the shadows of the frozen north. Luna had begged him to save the unicorn tyrant, and even though it didn't seem like Sombra radiated any darkness, there was no denying he had a lot of it just from his eyes. He had two objectives: save the Crystal Empire and stop Sombra from taking it over again, while also trying to save him from the darkness. The second of them seems to be impossible if he was right, and for Luna's sake, he hoped he was wrong.
Once Sora and Twilight grouped up with the rest of their friends, they told them that they were going off to the recently returned Crystal Empire, all of them understandably confused since no one has ever heard about it since its disappearance. As they boarded the train heading northbound to where the empire was located, they explained who was trying to take control of the crystal kingdom, though Sora had told Kairi and Riku about Sombra and his darkness in private, keeping his and Luna's relationship to himself. It would be bad enough for the young alicorn sister if word spread that she had been dating a madpony with darkness at his disposal. Heartless would definitely show up around Sombra, and with a millennium of being trapped in darkness, there's no telling what powerful Heartless could appear.
After several hours riding on the train, the locomotive arrived at the closest station in the frigid northern tundra of Equestria. A harsh blizzard blew through the area, lowering visibility as the land was pelted with the uncontrollable snowstorm. Everyone left the cars, being the only passengers headed northbound, searching around for any sign of the Crystal Empire.
"I can't see a thing out in this blizzard," Twilight said as she squinted her eyes from the frigid winds.
Rarity was the last to come out onto the station with Spike behind her, carrying several bags of luggage that belonged to the fashionista. "And all of you made fun of me for bringing too many scarves."
"Rarity, is now really the best time to think about packing clothing to someplace when we're in the middle of a crisis!?" Rainbow complained, the others agreeing with the pegasus. "What's the point of trying to look fashionable when it'll just get ripped to shreds if this Sombra stallion shows up!?"
"Well, Sora, Kairi, and Riku wear clothing when they battle," Rarity pointed out.
"That's because, for us, we need to wear something to not feel...exposed, both through combat and for public decency," Riku explained, trying not to reveal to them what the Keyblade wielders actually are. "And Rainbow's right; those clothes and scarves you brought along just to be someplace where we're only going to be at for a short while is ridiculous. Kind of pointless."
The white unicorn huffed, ignoring the criticizing pegasi. Since the only way to know if they'll get to the empire through this blizzard was going forward from the station, they trudged through the harsh winds and several inches of snow, Riku and Kairi watching everyone's back while Sora took the lead. The Keyblade wielders felt a very grim chill run down their spines, sensing a very powerful dark force somewhere out in the frozen wastelands. This darkness is far powerful than anything they've ever faced before, even rivaling that of Xehanort's.
"This is not good." Sora summoned his Keyblade, feeling like they were being watched through the blizzard. Suddenly, a low and guttural growl echoed around them, prompting Riku and Kairi to summon their Keyblades while the others huddled close to each other in fear. The stallions and pink unicorn slowly backed up, keeping their friends safe in a triangular formation, highly alert to where the growling came from. "Neither was that."
The darkness seemed to be getting closer, Riku spotting a black fog slowly approaching them through the blizzard. "He's approaching from my direction!" A pair of red and green eyes opened in the mist, leaking out a purple aura. The eyes leered at the three Keyblade wielders, sensing the light in their otherworldly weapons, making it growl louder. As he faced the demonic looking mist, black shadows began to rise up from the ground and surrounded them, but these weren't just normal Shadows. They looked like Shadows, only they seemed to take an equine form. "What the heck?"
"Pony Heartless?" One of the Heartless charged at Sora, the teen smacking it away with his blade. The others soon began to follow the defeated one's attack, trying to swarm the group, though the defenders were able to kill each one before they reached the mares and baby dragon. These Pony Shadows were stronger than the originals, and with Sombra around, more and more just kept coming. "There's too many! Girls, keep going forward! We'll cover you!"
Not needing to be told twice, the mares ran forward after Sora cleared a path for them, dragging a majority of the Heartless toward him with Magnera and destroying them with Thundaga. The black mist began to chase after them, hundreds of thousands of Pony Shadows leaking out from the gaseous shadow as the Keyblade wielders retreated.
"I think that thing might be Sombra!" Kairi shouted. "I didn't know anything could be this powerful! It's almost terrifying!"
"Guess that's the result of a thousand years of being trapped in darkness would do to you!" Riku added.
They kept running through the blizzard, Sombra and his Heartless creations slowly inching closer. Up ahead, Twilight spotted a familiar looking stallion appear out of nowhere in the middle of the blizzard, wearing a black scarf to protect him from the cold.
"Shining Armor!" Twilight exclaimed.
"Hurry! This way!" the recently married stallion shouted. "Sombra can't get through to the empire with the barrier set up!"
As the mares all ran in, disappearing through an invisible barrier that seemed to have kept the kingdom protected, Sora, Kairi, and Riku continued holding off the Heartless while avoiding Sombra's dark beams fired out from a curved red horn that grew out from his forehead. Many of the Heartless surrounded Kairi, sensing her heart of pure light a threat to them. The unicorn shoved them all away, unleashing a shockwave of light around her, causing Sombra to roar at the deadly light. The dark stallion flew toward her, intent on snuffing out that light before it could be used against him.
"Kairi! Look out!" Sora quickly flung his Keyblade, smacking Sombra hard in the face, distracting him long enough to grab Kairi and flew back away from him.
Riku stood by Shining Armor, slashing through more Heartless as they waited for Sora and Kairi. Sombra was hot on their tail, roaring angrily as he chased the two. Both stallions quickly leapt in as the spiky-haired pegasus and his girlfriend slipped through the barrier just in time, the dark gaseous form of the evil king slamming his face into the protective barrier of light, hurting him and keeping him and his dark minions from getting close. Sombra hovered around the barrier like a predator keeping its prey from finding a way to escape, leering at the newly arrived group as it disappeared in the furious blizzard behind him.
As the mares caught their breath, Sora and Kairi untangled themselves after crash landing into the safety of the magical barrier. "Thanks, Sora. What would I do without you?"
"Be a meal for a dangerous monster worse than the Heartless?" Sora grinned, earning a hard jab in the shoulder by the unicorn.
"And you still make jokes after a life-threatening moment." The couple now realized that the temperature inside the barrier was warmer, grass beneath them with barely a hint of snow around them. Kairi looked over to the others, her eyes widening at what laid far behind them in the distance. "Whoa...Is this the Crystal Empire?"
"Yes, it is," Shining Armor said. In the large blue barrier, the sun shimmered down on the crystal buildings and palace from the fields they stood in. The weather was sunny and warm, a complete contrast to the frigid snow and storms outside. The newly arrived ponies all stared at the crystal castle, Rarity with sparkles of excitement in her eyes, as Shining Armor stood before them. "Welcome to the Crystal Empire."