Twilight's ascension had been a life changing event, not only for her, but for many ponies.
One of those was none other than her brother, Shining Armour, king of the Crystal Empire and of the changelings.
When he had first started dating Cadence, he had been worried by their different lifespan, if her being immortal could be called so, but she had somehow reassured him. His latter second marriage to Chrysalis, even if technically it was the first, had done nothing to quiet his worries. And now, even his little sister would live forever, leaving him the only mortal in the family.

Sure, he thought while sipping a glass of hard cider There still are mom and dad, but we all would have outlived them both in any case, no?

He was sitting on his bedroom balcony, the chilly night air and the cold floor his only companions in his musings, induced by the invitation to her sister's 'alicorn party', courtesy of Pinkie Pie of course.

It had also been such a nice party...

"Shining, what are you doing out there?"

He turned around and saw Cadence wearing a lacy night gown and a preoccupied, even if clearly sleepy, frown.

"Nothing much, honey, just having a drink."

"Come back to bed please, it's chilly outside, you'll catch a cold."

"Sure," he said offering a smile.

The thought lied dormant for some months after that night, until his sister once again stirred it by defeating Tirek and gaining herself the title of princess of friendship.
This time though, there hadn't been Cadence, nor Chrysalis either, to pull him from his musings. And such dark thoughts usually don't end well.
And so, Shining, being the older brother of the most studious filly to walk Equestria's face in the last century, did the most obvious thing to him, or the most obvious beside asking Twilight, that is to say search the palace library for answers.
Crystal Clear, the librarian, did find it strange that his sovereign asked to be pointed to the section written by king Sombra himself, but after some months of abiding to the weirdest requests (one might never guess what queen Chrysalis liked to read in her free time), he simply accepted the thing with a shrug.
As Shining expected from Sombra's work, there were a number of ways to obtain immortality hidden in the countless pages that made up the tyrant's research journal, but the largest part of those required things that a stallion of his morality wasn't going to accept, like drinking the blood of seventy-six point four virgin mares, or desecrating the mortal spoils of a slain paladin with a pear, or dressing in a pink frilly dress and do a silly dance (the fact that this was supposed to be done on the corpse of a loved one did not help in the least). This left him with only one option.

"So, I need to somehow find an exact duplicate of myself and siphon his life force? And apparently this doesn't even kills him, good..." pondered aloud Shining hidden in a safe place "Wait, where do I find another me?"

"Shiny dear, are you done in the bathroom?" asked Chrysalis' buzzing voice from outside the bathroom door.

Once again, it was his sister's feats that brought him the solution: her travel in the land of humans and the notion that apparently there was a clone of everypony there gave him his best opportunity at finding a perfect duplicate of himself. He only had to wait thirty moons.
Yet, soon enough, his plan started showing its faults: two years and half of wait for the mirror to connect again, a window of three days to find his clone in a whole new world, and the mirror being moved to Twilight's new castle.
But fate decided to be generous with the young ruler, and sent him a sign to set his plan into motion. A very lavenderish sign, in a purple envelope.

"Listen here dear," said Cadence sitting in her throne "Twily has apparently returned to the world behind the mirror and Pinkie is organizing a 'welcome back party'."

"Are we all invited?" asked Chrysalis idly playing with her breakfast, consisting of peppermint cookies and warm tea.

"Yes, but we cannot exactly leave the empire and the hive without ruler," pondered aloud the other queen.

"Then I'll go: I haven't seen my sister since the Equestria games after all..."

"I'm okay with that," agreed the changeling with a shrug "I have to keep an eye on the hatchlings anyway. And you promised to help me Cadence, so don't try to run away!"

"Fine," sighed the alicorn visibly deluded.

"Don't you two worry, I'll be fine. What can possibly go wrong?"

Of course, that's exactly the kind of phrase that alerts fate to make things go south, but since Shining's plan was already pretty promising by itself, fate felt satisfied and let it go.

Around a week later, Cadence was once again sorting their mail as Chrysalis occupied herself with a sick looking little changeling, this time during a pause in court hours rather than breakfast.

"Chrissie?" asked the alicorn after having red a certain letter.

"That note of worry in your voice should tell me something, I'm sure, but little seven-thousand-sixty-three here is occupying my mind," answered her fellow queen.

"Shining is still in Ponyville, right?"

"Well, he's not here, so I'd say yes."

"Then why is Twilight writing that he forgot his bag when he left two days ago?"

"Because your sister-in-law is finally gone coo-coo in the head?"

"Our sister-in-law isn't mad, Shining has disappeared!" said Cadence grabbing the other by her shoulders and shaking her.

"Calm down, ponies don't disappear like that!" said the other freeing herself "He was escorted by three guards and two more changelings under cover, none of which did gave news of heading back by the way, there is no way he left Ponyville unnoticed, nor he could have been ponynapped."

"Then where is he?"

"The changelings and the guards say he never left the palace... This doesn't make much sense."

"What do we do?

"We go there and find him, that's what!" said Chrysalis stomping a forehoof "And then we scold him."

'Shining Armor', or better, number Two watched the train leave the empire only station and let out a sigh.
He turned around and saw two other changelings, number Three and Four, wearing the same exact disguise as himself and sighed again.

"Guys, this whole 'replace us while we're gone' thing is already stupid, don't make it worse, please..." he asked in an annoyed tone.

"Then change disguise, just like number Four here," suggested number Three with a shrug.

"What? Why should I play the part of one of our worthless queens? Let's call queen Ashley and put a stop to this masquerade!" lamented the third general.

"Hold your tongue when talking of the queens!" roared Two "Both of you, change disguise now!"

"And why shouldn't you do it? Only because you were born twenty seconds earlier?" protested Four.

"I'm not playing the girl!" shouted Three stomping a hoof and buzzing his wings.

This is going to end so badly... thought the first changeling facehoofing.

Author's Note

So, here we are after so long

I cannot say I will keep up the release rate I had for the first two stories, but you'll get the chapters as soon as my editor finishes reviewing them

I really hope you like this one, it took me forever to come up with this concept