Cadence drifted to the floor. "Okay, just what exactly are Kamui?"
The dress didn't answer for a while. Then:
"What is a Kamui? To answer that question, one must also ask a fundamental question: what are Life Fibres?"
She glared down at the dress. "Alright. What, exactly, are Life Fibres?"
"Life Fibres come from another planet entirely. Essentially, they are an almost symbiotic life form- in exchange for an increase in power, Life Fibres consume nerve energy. Unfortunately, if Life Fibres actually enter the body of their host without preparation, then the host will shortly die. That is why they evolved to be clothing. Ponykind did not choose clothing; rather, clothing chose you."
Cadence frowned. "So you're an alien?"
"Yes, and a benign one at that. My daughters share my personality, but it's unfortunate that Junketsu is too one-track minded to use my gifts correctly. As for the Shinra Koketsu... no. Shinra Koketsu was killed. I made sure of that."
Before Cadence could probe further, the door suddenly burst open, revealing Luna in her standard attire. "HELLO NIECE CADENCE! HOW ART THOU-"
She then spotted Senketsu and she froze. Then, the blood vessels in her eyes started to bulge.
"Um, Auntie Luna...?!"
She started to take in deep breaths. "Cadence, please remove thy clothing."
"W-what?"
Luna nodded. "Thou heard me. Remove thy clothing. He's a threat to Equestria."
Senketsu turned his baleful eye on her. "It's a pleasure to see you again as well, Luna. How are you, Nyx?"
"Hello Dad!"
Cadence's eyes bulged. "I-is that-"
"Yes."
Cadence glared at him. "What exactly did you do?"
Luna frowned. "Cadence, Senketsu very nearly doomed Equestria to fall into ruin due to his lies about the Primordial Life Fibre."
"Primordial Life Fibre?"
Luna nodded grimly. "Indeed. One thousand and five hundred years ago, the being known as the Primordial Life Fibre appeared from the oceans of Equestria."
She flared her horn, and images appeared- of what looked like a huge, glowing orange spool of thread, appearing from the sea.
"It gained a foothold, and eventually corrupted several beings. Senketsu elected to fight the being, but he neglected to mention the power of his traitorous child- the Shinra Koketsu!"
A long, white, bushy robe floated into view, lined with red and hooded. "With its very being spun from the Primordial Life Fibre, the Shinra Koketsu dominated the world. The thing is, due to Senketsu's own reckless creation, it possessed the ability to completely nullify even the most powerful of the Kamui. Thanks to that, it meant that we had to fight without the Kamui, and though we might have had the power to stand against a normal Kamui, the combined power of the Shinra Koketsu and the Primordial Life Fibre meant that... we were beaten."
Cadence looked down at Senketsu. "Is this true?"
"Yes, it's true. Shinra Koketsu was my most precocious and powerful child, formed from the Primordial Life Fibre itself. Shinra Koketsu possessed the power of Complete Domination- no Life Fibre creature could stand against its might. This, combined with it being even more powerful than myself, meant that there weren't many who could stand against it. Plus, Discord had worn the garment. Can you imagine how powerful he was at that point? Even when the Primordial Life Fibre was destroyed did he show any real fear of being beaten."
Princess Luna nodded, not taking an eye off of Senketsu as she prepared a spell. "Not even we could do any really meaningful damage without the Elements of Harmony. Only Senketsu was able to resist the power of his child, and destroyed it. He then had the gall to chastise us, and boasted of his adaptive abilities, and the fact that he was the only being that could fight against another Primordial Life Fibre. We fought him there and then, and though it was an uphill battle, we eventually prevailed. We bled his Absolute Domination ability off with the Elements of Harmony, and we sealed him beneath Canterlot."
Her expression grew grim. "But the Primordial Life Fibre will never attack us here again, I know it."
Senketsu shook his head. "You're wrong, Luna. The Life Fibres are capable of traversing the void of space. Another one will come, and when it does, you'll need me."
"I grow tired of this. Senketsu, if thou art still the gentlestallion thou were, then endanger my niece not."
Senketsu snorted, already removing himself. Cadence squeaked in embarasment and ran to cover herself up. "Though it may lead to my imprisonment yet again, I shall never willingly endanger an innocent again. Speaking off..." He affixed a glare on the Kamui that Luna wore. "NYX! I heard that you drove Luna into madness!" What do you have to say in your defence, young lady?"
"Y-young lady?! I'm just as old as you are!"
"WRONG! You're twenty years younger than I! Bah, it doesn't matter. I'll fight you both if I have to."
Luna frowned, flicking the glove switch.
Cadence and Senketsu watched her transform. When it cleared, her appearance had significantly changed. Rather than an elegant, form-fitting dress, she wore a tight corset, breasts threatening to escape the tightness of it. High stockings with garters stretched down her legs, and her arms were covered in black lace.
"Life Fibre Synchrionize, Kamui Nyx!"
Senketsu snorted. "Life Fibre Synchrionize, eh? It seems as if you are correctly wearing my daughter. You are truly wearing her now."
Luna nodded. "Indeed. In order to stop you, Senketsu, there is nothing that we will not do. Whether that is strip in front of the populace, or degrade ourselves in front of Discord, we have no limits."
Senketsu grinned, shooting forwards on a blast of magical energy. He spun around and around rapidly, the very air around him twisting and turning.
"SENKETSU DRILL!"
Senketsu's P.O.V, 1,505 years ago.
I looked between the two. "... so you're sisters, huh." The shorter, dark blue one nodded.
"Indeed, that we are."
I shook myself. This was more than a bit weird. "But... you look nothing alike! You're white," I pointed at Celestia, "and you're dark blue. How are you related?"
Luna frowned. "I represent the night, while Celestia represents the day. 'Twould be strange if we weren't those colours." She looks at me. "We have never felt a magic like yours. Pray tell, what is it?"
"I am made of Life Fibres, a race of aliens who come from outer space." The truth is stranger than fiction, after all. They just stared at me as if I was a talking, magical dress that fed off of blood...
OH WAIT!
"Speaking of my strange origins, I'm going to need to feed off of blood. Just a little bit should do me fine. If that isn't too much of a problem."