The two Princesses stared at him with wide eyes. After a few heartbeats Celestia finally recovered and asked:
"Are you sure?" and when Matt nodded, she added: "How can you know about this? Twilight wrote me in her letters every bit of information you told her about Azeroth. If there were creatures like changelings in your world, you would have mentioned them to her, seeing as they resemble ponies to some extent."
"Let me start from the beginning, Your Highness." answered Matthias, frowning. "When I fought Chrysalis, I looked through the window and saw the other changelings. The way they moved, fought... it made me realise that I saw that already."
"You realised that they are from your world by the way the changelings moved and fought?" asked Princess Luna. "What about their queen?"
Matt shook his head.
"She looked and acted as if she was pony, or at least, she was more pony than what I think her ancestors were."
"Do you mind telling us what those ancestors are, exactly?" asked Celestia, frowning.
Matthias closed his eyes.
"Long ago, a race of intelligent insectoid creatures was born on Azeroth, called Silithids. About sixteen thousand years ago, the fallen Old God C'Thun recognized their appearance, and attempted to sunder the world that it once held in its merciless grasp. The Old God created avatars from the Silithid in its own image. These avatars were eventually known as aqir. They created an empire — the civilization of Azj'Aqir. These clever insectoids were greatly expansionist and incredibly evil. The aqir were obsessed with eradicating all non-insect life from the fields of Kalimdor. The trolls’ empire - I told Twilight the history of trolls, didn't I?" he asked to be sure, not wanting to start another tale. When the Princesses nodded, he continued: "They fought them for a thousand years, but never succeeded in winning a true victory over the aqir. However, due to the trolls' persistence, eventually the aqiri kingdom split as its citizens fled to separate colonies: Ahn'Qiraj in the southern desert of Kalimdor, Azjol-Nerub in the northern wastes of Northrend, and one more in the Dread Wastes of Pandaria. Possibly due to the environment, the three groups eventually became completely different beings, though whether this was a divide that had always existed remains unknown. The more insectoid qiraji have taken up residence in Ahn'Qiraj, the spider-like nerubians populate the northern city of Azjol-Nerub, and and mantis-like mantid live in the Dread Wastes of Pandaria."
He finished and glanced at the Princesses. They seemed to take everything in rather well.
"So you think that the changelings are the fourth offshoot of aqir that somehow found their way into this world." said Celestia, nodding.
"Yes, although how that happened is beyond me." Matt said, frowning.
"That is impossible!" "shouted Princess Luna suddenly. "If what you said is true, then the aqir race split around fifteen thousand years ago." she waited for him to nod, and continued: "The changelings were first discovered a little more than thousands years ago. I remember it well, because... it's one of the last memories I have from that time before I became Nightmare Moon." she added, shaking a bit.
"Sister." told her Celestia, placing her hoof comfortingly on her shoulder, "stop thinking about it."
Luna gave her a weak smile.
"Luna raises a good point." she said, turning to Matthias.
"Maybe you didn't notice them, Your Highness." Matt replied, shrugging. "They are shapeshifters, after all."
Princess Celestia shook her head.
"Before our reign, Discord ruled Equestria." she reminded him. "If the changelings were here at the time, he would have know about them, and revealed them. He would have found a great joy in telling ponies about creatures that fed on their love. The changeling were discovered some ten or twenty years after we defeated him."
"Maybe..." Matt pondered about it. "Somepony like an incarnation of chaos wouldn't be fooled. But if that's true, then how?"
"How long did Discord's reign lasted?"
"About fifty years."
"A thousand years ago... " he said aloud, pacing. "Sometime after you defeated Discord and before Princess Luna became Nightmare Moon, the changelings appeared, a thousand years ago..."
He whirled as the realisation struck him.
"Wait, all of this happened during a single century thousand years ago?!" he asked the Princesses with his eyes wide.
They shared a look, startled by his reaction.
"Yes." Princess Luna answered his question. "What are you..."
"And when did you return?" he interrupted her, forgetting about formalities in his panic.
"What?"
"When did you return from your banishment to moon?"
"It was two years ago." answered for her sister Celestia. "Why do you ask?"
"I couldn't be... could it?" Matthias closed his eyes as he forced himself calm.
"A thousand years ago, the Old God C'Thun nearly awakened, and the qiraji waged war, trying to dominate the continent of Kalimdor. The night elves and eventually dragons opposed them in what became known as the War of the Shifting Sands."
"You think that it have something to do with what was happening here?" asked Celestia, alarmed.
"As much as I find it hard to believe that, yes, that's what I think. And there is more. That war ended when the Scarab Wall was erected to contain the qiraji within the city of Ahn'Qiraj. But, two years ago, the Old God began to awaken again." Matt added, looking at Princess Luna. "A Second War of the Shifting Sands took place, as the Azeroth realised that the only way to deal with the threat once and for all was killing C'Thun."
Luna's eyes went even wider as she understood what he was suggesting
"So, my escaping from the moon, as well as me turning into Nightmare Moon." she asked, shaking., "was because of that... Old God waking up?"
She looked like she was sick.
"I don't know, Princess." Matt said, bowing his head. "But I know this: when I first heard about what happened to you, I immediately thought about Old Gods, but until now I haven't thought that to be possible."
"Luna?" asked Celestia, worried about her.
"I'll be fine, sister." she replied, forcing herself to be calm.
From the look that Princess Celestia gave her younger sister Matt figured that she was as much convinced by her words as he was, but didn't pressed her.
"How would all of that be possible?" she asked Matt.
"I have no idea, Princess." answered Matt, frowning. "Although it is not impossible to travel to other worlds, as there is another world - or rather, remains of a world - connected to Azeroth called Outland through the gate known as the Dark Portal, it would take a similar connection for the Old Gods' influence to reach here, and I'm sure that there is no Dark Portal near Ahn'Qiraj."
"And what about the changelings?"
"That's another thing that I don't understand. None of the aqir descendants have shapeshifting abilities, and they don't feed on love. At least, to the limits of my knowledge."
"And how limited is your knowledge, exactly?" inquired Princess Celestia.
"I know next to nothing about the mantid, unfortunately, but on the other hoof, my knowledge about qiraji is fairly vast. As for nerubians." he added with a smirk, "I most likely know more about them than anypony, beside the nerubians themselves."
"Quite a feat for somepony who repeatedly says he's not a scholar." noticed Celestia, but she shook her head. "I guess it doesn't matter. I wonder, though - do you think that's why you're here? So you could help us with them?"
Matthias has been wondering about it for some time, too.
"I'm... not sure." he said, frowning. "You said that I would know what it is that I have to do when the time comes, Princess. I still don't."
Celestia nodded and was about to say something, but her sister interrupted her:
"Why did you heal her?"
"Excuse me, Your Highness?" asked surprised Matt.
"You healed the Queen of the Changelings. Why?" repeated Luna. "Not only she tried to take over Equestria and harmed many ponies, including your friends, but also is a descendant of one of the most violent race on Azeroth. And you healed her horn, Why?"
Matthias smiled and closed his eyes.
"I am a paladin, after all. My obsession with redemption goes beyond the insane. And the queen didn't seemed that evil to me... compared to those on my world." he added, noticing that both of them were about to protest. "All she did was for the good of her subjects, after all."
"You're a strange one, Matthias." said Princess Luna after few seconds.
"Maybe." told her Celestia. "But I can see his point. I just hope it won't come back to haunt us later. As for the possible connection between our worlds... I will have to look into it. Maybe in one of the oldest scrolls there will be something that could shed some light on this mystery."
"I will leave this to you then, Princess." Matt said, bowing.
"I have one more question, though." added Celestia. "Why didn't you want to mention this near Twilight and the rest of your friends?"
"I... still feel guilty about how terrified Twilight was after she saw the vision of Deathwing." Matthias said uncomfortably. "I prefered to spare her and the others more horrors of my world."
"I guess that's understandable. But Twilight is stronger that you think. While she was shaken by that vision then, she would probably be fine now after hearing such news. And you don't need to feel guilty that she saw that." she added, looking down. "If anypony is guilty of that, then it would be me."
"You, Your Highness?" asked surprised Matt, not understanding.
"That book where Twilight found the spell to enter your mind, the 'The psychological art of mind's magic', was forbidden by me to read over forty years ago, soon after it was published. I was sure that all copies of it were either destroyed, or kept in the locked part of Canterlot archives. I had no idea that there was a copy in the Ponyville library." she sighed. "I allowed Twilight to keep the book, although I forbade her to use spells from it unless it would be necessary."
"Why did you forbid this book to be read?" asked Matt, curious.
"Aside from the fact that entering ponies' minds is an invasion of privacy? There are very dangerous spells in it."
"Makes sense."
"Lets return to reception." said Princess Celestia, her horn glowing. "I don't see any reason why we shouldn't celebrate with everypony, even in light of those revelations."
She flashed her horn and Matthias found himself once again in the courtyard.
"Will you tell Twilight and the others about it?" he asked Celestia.
The alicorn pondered that thought for a moment.
"Not for now, I think." she said finally. "I would prefer to research about this before I will let anypony know."
She glanced at him.
"Then I won't tell anypony either." Matt said, bowing his head.
He glanced at everypony. Shining Armor and Cadance were still dancing, but were now surrounded by many other dancing ponies, including his friends.
"Are you sure you're alright, little sister?" he heard Celestia ask Luna.
He turned his head to them. Princess Luna was gazing in front of her with empty eyes. She stirred as her sister called her.
"I am alright, my sister, it's just..." she stammered, looking for right words. "To think that all of that happened to me because of some evil being waking up, manipulating me, just..."
"Look at it this way, Your Highness:" said Matt as she once again stopped to look for words that would describe what she felt. "it wasn't entirely your fault."
Luna looked at him, surprised.
"I had became evil once myself, so I know how you must feel." Matthias told her, coming closer. "You feel used, sick, weak, because you allowed that evil to control you. But, the fact that you were controled, means that at least it wasn't entirely your fault. It's better than becoming evil on your own, I think."
As Luna gazed into his eyes, Matthias knew she was trying to believe what he said, but also knew that her guilt made her hesitate.
"You will probably never forgive yourself for that." he told her, despite that he could see tears in the corner of her eyes. "But you are luckier than me, Princess. While I will forever be remembered in my world for who I became, you were given a second chance by fate here, in Equestria, and you have your sister beside you."
Princess' gaze moved from him to her Celestia, who smiled in response.
"Thank you, Matthias." finally said the Princess of the Night, smiling as well, although it was a weaker version of the smile her sister gave her.
But at least, it was an honest smile, not a forced one.
"My pleasure, Your Highness." Matt answered, bowing. "If you would be so kind to forgive me, I would..."
"Of course, Matthias." nodded Celestia, allowing him to leave.
Matthias once again bowed and made his way to the celebrating ponies.