"Why are you scared of magic?" Sparkles asked.
"Magic? These are black arts used by the Dragon Queen!" Twilight looked back to the perpetrator and put the tip of her spear just at the pony's neck.
"Wait! Wait!" Sparkles hurried over and did her best to attract Twilight's attention. "They're not black arts! It's magic that unicorns use-Well...everypony can use it, but unicorns can actively manifest magic into various forms."
"That's not magic!" Twilight looked at her victim and bared her teeth. "This is magic," she growled.
Magic ran along the lines of her horn and her legs to reach the spear and charge, but the other guards weren't having and closed in to tackle her.
"Stop!" Celestia yelled in the Royal Canterlot Voice. "She is obviously from a different era of thought and place." Celestia stepped in front of Twilight and leered at her. "I truly do not know what has happened to make you as you are, but we need to analyze you better than this and help you relax, otherwise you're liable to destroy everything around you like a frightened animal."
"I'm not an animal."
"You're acting like one!"
The lavender narrowed her glare at the alicorn and reluctantly retracted her weapon. She put her armor on her back and went next to Sparkles.
"When is this 'body scan' or whatever medical procedure you mentioned?"
"When can do it r-right now, if you want," the mare squeaked.
"Then let's go. I don't want to be in the presence of the imposter any longer."
Sparkles wanted to say something, but it only came out as a brief stutter. She accepted the situation and brought the mare and four guards along with them back to the surface, leaving Celestia to marinate in a pool of various emotions.
The group walked through the grounds towards a small building next to a growing field of bushes. Nopony but Celestia and her gardeners knew precisely what it was for, but there were quite a few statues placed around in front of them, including some aberration of parts that seemed to be singing for some sort of choir. Twilight took notice of it but never really recalled seeing on of them in her time. They were probably wiped out just like all the rest.
The small building only had one room full of medical equipment, such as syringes, tongue depressors, scalpels, tables to place patients on, desks, and chairs. There were several different plants akin to giant flytraps, placed upon drawers lining the walls. They were vibrantly colored, something that made them clash with the white room and stick out like an uneaten cake in Celestia's pantry. Several shelves were attached to the walls above the drawers, but Twilight couldn't fathom what was in there. A large group of windows comprised the wall behind the main desk of the Sparkles, allowing plenty of light to enter the room.
"Put her there," Sparkles told the guards.
They moved her to a large, stone sculpture sitting in the corner of the room. Its central body was quite a bit high, at least the height of Celestia, and two, smaller 'wings' of stone flanked the central body. It was polished and smoothed, like marble, and Twilight noticed several transparent veins running across its surface which resembled glass.
"What's this?" she asked.
"It gauges your magic power," Sparkles answered.
"How?"
"You'll see--Wait. You know about magic?"
Sparkles and the guards stared at her with the 'loudest' expression of confusion they could muster.
"Well, yeah. If I didn't have magic I wouldn't be able to use this spear."
"Then...Why are you so terrified of magic?"
"I just told you that I'm not."
"But when the unicorn guard was levitating--"
"THAT'S NOT MAGIC! That's black art of the Dragon Queen." Twilight bellowed in rage.
Sparkles shaped her face into an 'o' shape as she tried to comprehend this pony. "She says she uses magic...but she doesn't like spells used with magic. There has to be a logical explanation to this...but...that spear she uses might be a clue on how she uses magic. First, I need to gauge her powers, first, and hope that they're stable."
Sparkles cleared her throat and gestured Twilight to move next to the stones and sit next to them. The doctor took a red jewel from her saddle bag and held it in her mouth while she moved towards a circular stone with a large indentation in its center. The jewel started glowing brightly and the glass tubes on the monolith started glowing the same shade of red, engulfing Twilight in a red sheen. The doctor decided to use this opportunity to extract some blood from the unicorn who yiped in pain and glared at her 'attacker'. Sparkles shrugged in embarrassment and took the syringe to analyze it using the various elements of the plants dotted around her office.
The guards kept watch and observed the monolith do its work while Twilight sat still, too nervous to move anything but her eyes. Sparkles crushed some of the leave and petals of a blue and green plant and poured them with a vial in which she placed some of Twilight's blood. The powder was well mixed into the blood and left on a holder for a short moment until she started to hear flickering.
"Doctor, is this normal?" one of the guards asked.
Sparkles turned to see the lights flickering on the monolith before they eventually extinguished.
"N-no. That's not normal." She turned to her vial and realized that it remained darkened by the substances she placed in it. "This isn't normal either. The blood should be glowing slightly and letting out some sparks of magic. This plant removes magic and is a good way to test how much magic someone has, but it's barely even glowing at all."
A wide smirk grew on Twilight's face, but Sparkles didn't see the same amount of humor in it. She and the guards went back out of the office and bumped right into Celestia who was sitting patiently, awaiting for the results.
"What are the results?"
"P-princess? What are you doing there?"
"I was concerned. I wanted to now everything about this pony that I could possibly get."
"Well, she isn't telling us anything about her past." Sparkles turned slightly and tucked at her throat fur with her wing. Twilight 'harumphed' and looked away from the doctor's look of worry. "But...she is anomalous. Whatever she's saying might be truer than we initially thought."
Celestia was very curious now. "Oh?"
"She...She has no magic flowing through her."
"But...that would mean she's dead, no?"
"No. Even the dead have some form of magic -even if not entirely their own- passing through them, but she has confirmed that she uses magic for her spear."
"Then that would mean that ponies where she is from have either developed something akin to magic and haven't realized it, or--"
"She has an impossibly high resistance to magic, diluting any she has or even any spells that..."
The two mares looked at each other in glee. An epiphany hit them, one that would kill two stones with one bird.
"Twilight," Celestia spoke. "I would like to see your combat prowess and how well you can fight against both pony and magic. Would you permit this?"
"Yes, but don't get any ideas. I know how to pay attention to the things around me." Twilight flipped her spear behind her should and started filling it with magic. It point at a guard behind her who was approaching with his spear ready to jab at her. "And tell your little colt wearing foil that he is far too clumsy to attempt discreet assassination."
Celestia leaned casually and glared at the guard who shrunk down and hid away in the nearby bushes. Everyone went to one of the open training grounds for the guards after that incident. It was a large square of brown dirt surrounded by a flimsy wall of wood better suited for holding in large livestock. Anyone could go through them, but that was the purpose. Several guards were leaning against the fence and cheering on comrades wrestling in the middle. When the captain saw who was coming, he shouted to the others to stop immediately and salute.
"Captain, I need to assess this pony's fighting capabilities," Celestia said.
"Who, this--Wow. That's...a lot of battle damage," the captain cringed.
"Must I really fight them? They are clearly far too inept to be even fighting the young ones of my home," she winced.
"What?!" the captain roared.
Celestia tried to reason with the stallion. "Captain, please. She's--"
"Alright, then. We're going to do this like a real battle. I'm keeping my armor on and using my magic and sword. You use whatever. I'm not letting some damsel with a few nicks in her fur mock my troops."
Twilight scoffed at him and donned her armor, all while Celestia had facehoofed. The two hopped into the arena, much to the cheering of the guard. Twilight sat in place, had a foreleg wrapped around her spear, and leaned her head against it while the guard prepared himself with stretches.
"Alrighty then, little filly. I'm going to show you what proper training from the Royal Guard can accomplish."
Twilight didn't react to the charge nor the yelling of the stallion coming at her, but when he tried to jab at her with his sword, she moved her spear slightly towards the middle of the impact and stopped his sword.
"You're too single minded. You'll never be able to fight dragons and ejge this way."
"What?"
Twilight ducked and sweeped at the stallions legs, making him face-plant into the ground. The lavender unicorn casually moved away from him while the stallion punched the ground and jumped up.
"Fine. I was being easy on you, thinking you were just full of yourself, but now I can see that you have some form of training. Then I'll use my magic as well."
The stallion created a blinding flash of light and charged into Twilight, expecting her to be incapable of seeing, but she blocked his sword strike and brushed it aside then punched the stallion in his neck and jumped away.
"Ah! How?!" he yelled.
Twilight tapped her helmet. "Film made the oil pouch of a dragon. Helps filter bright lights."
"The what of a dragon? You're making that up!"
The stallion attacked Twilight once more, but this time, he went for consecutive blows rather than a single, decisive attack. The lavender unicorn spun her spear around her neck and forelegs to block every strike the stallion threw against her and would hit his horn when he tried to summon any magic, causing him great pain and destabilizing the spell. The captain's anger was growing to extreme levels, so much so that he bounced away from Twilight and blasted her with a powerful ball of magic, destroying almost the entirety of the training grounds, creating plenty of smoke, and nearly killing several guards that were present. Had Celestia not been there to pull them out of the way, they could have well died.
"ARE YOU INSANE?!" Celestia bellowed.
"I...uh, I," the captain stuttered.
"YOU NEARLY KILLED EVERYPONY THERE! It will be a miracle if the mare is even alive after that, anyways! She had important subjects we needed to learn, and you let your anger--"
"That's all you can muster?" a voice spoke from the smoke.
"Wh--" Celestia tried to formulate a sentence but couldn't.
Twilight was still standing in place, and she hasn't received any damage from the attack.
The captain lifted a hoof and, trembling, pointed it limply at Twilight. "H-how?"
"Something like that wouldn't be able to pierce armor made from dragon scales and leather."
"DRAGON?!" Everypony shouted.
"The more I learn from her the more questions I get from her. Yet...I haven't felt this curious about anything since I was a young filly," Celestia thought to herself.
Elsewhere in Equestria, far away from Canterlot, another portal opened up in the countryside, but a tiny pony did not come through it this time. Instead, a large dragon punched through and crashed into the land below. She rubbed her head an groaned in pain.
"So that is what time travel is like, huh? It's painful." She looked around to see a lush, green, hilly plains around her with a few groups of trees breaking the uniformity of the lands before her.
"I haven't seen lands like this in centuries, and there is even a small village over there. A good place to start and learn exactly where I am, but first."
The dragon focused hard and her body started to shrink down and crush itself. After much cracking of bones, she was finally done. Gazing at her forelegs, she saw that they still had the length of a pony's despite still ending in sharp claws, as well as a long tail ending in a tuft of fur.
"I haven't used this form in just as long. Time to get started," she said to herself.