Prologue
Chaos spread throughout the area as crystal ponies fled for their lives. A grey unicorn stallion cackled as he approached the crystal heart. He had a pointed dark red horn that curved, his eyes were red with green and purple dark magic coming out of them. He came close to stealing the heart, when a mare's voice interrupted.
"Sombra!" The stallion turned to see a unicorn, the ruler, Princess Amore. She had a pale red coat and amber eyes. Her mane was straight then ended in large curls. The colors of her mane were a raspberry color pink which faded into a moderate blue at the ends.
"Well, well, well, if it isn't my challenger," sneered Sombra.
"You do not have to steal the crystal heart Sombra. You still have time to change your fate," Amore said calmly. "I see you as good-hearted. Yet, the path you are taking may lead unto your doom and destruction."
Sombra frowned, and then his eyes narrowed. "You knew all along, DIDN'T YOU?!" Sombra screamed. "All this time I could've not become this way. But thanks to you I have!"
"Now, Sombra...," began Amore.
"Use your motherly tone on me, Amore," scoffed Sombra. "Besides, it doesn't work on me anymore. These crystal subjects belong to me, now!"
Amore glanced at Sombra straight-faced, hiding her intense fear. "There is still good in you, Sombra. I know it. You can overtake this darkness, and life can go back to the way it was. Take my hoof," Amore said as she held out her hoof. Sombra smacked her hoof away, as Amore's eyes widened, her fear finally showing.
"I don't need you! I don't need anyone! All I want is power. Lots of it! I see it now, Sombra, the most powerful King of the Crystal Empire! First, I conquer the Frozen North, then all of Equestria! These ponies have messed with me for the last time!" cackled Sombra.
"No, I won't let you do this Sombra! You can try to take over Equestria, but the Princesses will stop y-," cried Amore.
"They can try. Heck, all of Equestria can go against me. Either way, I'd win against them!" mocked Sombra. "And this is how I'll do it!" And with that, he put the crystal heart in his sack. A change came over Amore then. Her magic began pouring out of her as her eyes glowed white and pupilless. It lifted her off the ground as Sombra absorbed her power. When Amore collapsed on the ground once more, her eyes widened in shock to see that she had no cutie mark upon her flank.
"Now that you're powerless," began Sombra as he cackled. "I can do this!" His horn ignited as he lunged for the princess. Amore stood on her feet, as Sombra threw a black crystal that began to crystallize into stone. She screamed as she couldn't move, her left forehoof lifted up as she became a stone statue.
Meanwhile, Sombra hadn't noticed that a certain mare had gone to the princesses for help.
"Thank you for inviting me over for tea, Your Highnesses," said a unicorn.
Celestia chuckled. "How many times do I have to tell you, Prisma? You don't have to call us that. You're the same ranking as us."
"But I'm not an alicorn!" Prisma protested. "Alicorns are supposed to be princesses! How are unicorns princess-worthy ponies?"
"Depends on how strong thy magic is," Princess Luna implied. "Also, if your elder sister is a princess." Luna shot Celestia a look.
"Oh stop, Luna. You were born an alicorn along with me."
Prisma rolled her eyes playfully. She was a unicorn who had large curls around her ears along with a straight-like longer layer that ended into two curls in which one was longer than the other. She had a coat that was an extremely pale pink, nearly as white as Celestia was, if not a shade darker. Her mane was a dark raspberry pink, along with an arctic blue thick strip in between which was the same color as the crystal heart. The last part of her mane that held the shorter curl in the front was a royal purple. Her eyes were a strawberry color, being a pinkish red.
"-and I was like, who me? Yes, sir I am an alicorn. Thank you for noticing!" Celestia finished as Luna in annoyance, rolled her eyes. Prisma only listened briefly, because she heard... hoofsteps nearby?
"Princess... Celestia... Luna...!" a unicorn gasped as she entered the room they were having tea in. She was a lilac colored unicorn with a baby blue mane.
"Radiant Hope?" Prisma asked upon seeing one of her sister's subjects. "What are you doing all the way in Canterlot?"
"Sombra... siege... Crystal Empire... Princess Amore... stone," panted Radiant. Prisma's eyes widened as she looked at the alicorn sisters.
"We must stop Sombra, sister," Luna said.
"Yes, but you two will come with us," Celestia said, looking at the two unicorns.
"We can't fly though," Prisma said.
"Pftt," Celestia said as she grabbed hold of Prisma's front hooves. "Sister, you take Hope." As Celestia took off, Prisma grasped to her front hooves as she flew, refusing to let go. When they got high enough up, Prisma became enveloped in a yellow aura as Celestia placed the unicorn princess upon her back. "Hang on, Prisma." Luna caught up beside them, holding Radiant by her scruff.
"I could've just teleported," she remarked as she folded her hooves.
Prisma caught sight of the Empire, her eyes narrowing. Just as Celestia was about to land a few feet off the ground, Prisma leapt off and faceplanted into a pile of snow. "Uggh," she groaned. "Me and my clumsy self."
"Sister, didn't thou say what happens to the Empire when the Heart is-," Luna began.
Prisma gasped. "The Crystal Heart! Amore!"
The unicorn princess dashed for the room with the Crystal Heart. When she did, her eyes filled with horror upon what her sister had become.