The ruins of the Crystal Empire, 3 days after the destruction of the Heart
Precious little of what was the Empire now existed in any larger pieces than pebbles, the catastrophic release of energies scouring most of the city down to a choking cloud long since blown to the windigos. Of what remained, the largest pieces were the occasional scrap of wall that once had been the central castle.
Amidst that jumble could be found the blasted remnants of what once had been a mirror-frame. That it still held a single jagged third of glass at the bottom could only be a testimony to the nigh-legendary construction it had once had before being battered by the arcane blast and ruined, untold energies forced through the portal until it gave way, violated in a way it was never designed to handle.
The shard twinkled and sparked like a filly's horn as something forced it's way through the shard and into the world. A hoof, the yellow fur pitted by dozens of scorch marks. It pawed blindly for purchase and found a loose stone, then a few bricks that had flash-melted into a somewhat solid grip. The leg convulsed, dragging a smouldering pony through the broken mirror to lay gasping on the rubble.
With a flash, the failing portal spat a last bright nimbus of magic into the skies. A few droplets of molten glass peppered the unfortunate unicorn's tail with a few more burn marks, who ignored them in favor of breathing air she hadn't had to magically create herself, or actual ground to stand on that wasn't hurtling through a void and trying to crush her on impact. The one eye that wasn't currently facing the ground rolled, looking around. Rubble, ash, ruin, destruction.
Sunset Shimmer took a deep breath to address the situation and tell the world what she felt after being tumbled about like an aura-covered pinball for days, unable to sleep, eat, drink (beyond a handy sports bottle that'd been stuck in her purse-now-saddlebag for gym class) or most forms of common sanitation. She was burnt and burnt out. She stank. And she'd spent the entire time watching the sucked-in, ground-up mess that had been Equestria High and it's surroundings as it'd been torn from it's place and reduced to a thin slurry of crumbled concrete and ashphalt to squeeze into the space between worlds.
She watched the rubble, because watching the hundreds if not thousands of -people- that had been in there when it happened would have driven any good creature stark raving mad. Their state of...mixture made an exact count impossible and equally sanity-breaking to consider.
BAAAAAAAAWWWWWWWWWWWW!
That is, she cried like a newborn, terrorized filly. As it stands, being the only living pony in the middle of the Crystal Empire, making a magical explosion and then howling like a baby isn't a bad way of attracting attention.
Hooves tapped on the rubble, and a rattle choked the young mare's cries to a strangled sob.
"Someone? Somepony? Can you help? WHY IS THIS ALL WRONG?"
The pony-head that poked over the half-melted pile of bricks failed to restore any faith in the universe. It lacked- flesh, a tooth, eyes (save for a glowing pair of red dots where they should have been), and the cackle of laughter the skeletal, reanimated corpse gave upon spying her was one of cruel joy and purpose. It's mostly-intact teeth showed a full set of sharp, pointed teeth...which the skeleton put to their purpose, and bit.
Fire burned across the back of Sunset's neck as the thing scraped skin and tore a chunk of mane clean out, giving her new reserves of energy that apparently had been hiding in the back of her head, filed under "absolute terror". She flung the nightmare away, then conjured a perfect summoning spell that should have burned the thing to ashes with the flawless precision that only a self-absorbed, power-hungry unicorn could provide.
Instead, the inside of her horn felt like someone had dumped boiling oil down the tip and into her skull as the spell misfired, sending motes of orange flames in every useless direction at once. Her panic and focus shattered by the burning pain that found it's way behind her eyes, she wobbled once, twice...and collapsed as she had nothing left to give.
A second bony remnant of the population canter-clattered onto the scene on three and a half legs to scent (if one could call the nose holes it pointed "smelling") the burnt, bloody flesh. Sweet, living flesh. The two mindlessly tangled briefly above the unicorn's broken body, clashing mouths as each tried to tear out the mare's still weakly beating heart.
A green, flaming meteor slapped into the three-legged corpse, shattering it and sending the other undead tumbling down what had been a street before a behemoth had pulled down the hospital atop it. It did not care, but simply rolled back onto the cracked bones of it's legs to charge at it's meal again, snapping and uttering that insane laugh once more. A second meteor obliterated the thing before it took two steps, then unbent it's legs and walked away from the bone-splintered crater. Together, they turned glowing blue eyes on the Equestrian girl.
A trailer of smoke curled from the ears of Sunset Shimmer to twist it's way through her saviour's leg. That is, in one side of the hole that showed above a chitinous hoof and out the other. The hoof poked. The mare moaned.
"Alive. She wishes evidence of the death here. Would a fresh body be enough?", a somewhat chitinous mouth spoke.
"A survivor would be better. There have been no others. Take her, and we wear pony-skins until she is delivered to the Blueblood, all glory to the Queen." With that, the first voice chittered agreement and two glimmers of magic cheated their forms into something false, yet real enough to touch.
Grey-and-armored, the pair of pegasi in tarnished guardsman gear bore the unicorn on their backs and vanished, but for the occasional glimpse of a flame-red tail. Canterlot was a long flight, but they had been sent flush with love from the nest. It would suffice, and the Queen would have more waiting when they returned with their prize.
---
Sunset Shimmer had clearly died and gone to pony heaven. Or recovered from a long bout of madness. She had a real shape, HER shape, with a horn and hooves and a tail as only the apex of creation could be born to. Her eyes were closed, but she lay on cloudlike softness, a feeling she hadn't known since the day she left through the mirror, years ago. Humans didn't sleep on clouds, no matter what their commercials said. That took pegasus down and a fresh cumulus. The room smelled, and she could actually -smell- again, not the claustrophobicly thick perfumes she'd have to hose herself with scent to notice, but the more subtle...notes...of a stallion?
An ache in her neck brought back memory, and she startled as her eyes opened to the sight of Blueblood's muzzle casually giving her the once over. In a bedroom. A very much STALLION'S bedroom.
The blankets snarled themselves into a ball of rather expensive 300-thread shreds as she covered herself and blushed furiously. Blueblood's near-nuzzle turned quickly into a solicitious sniff as he realized the sleeping beauty had awakened. While impeccably dressed, it was obvious that he'd had a hard day- a few bandages peeked out from under a velveted coat, and someone had bloodied the stallion's muzzle. Or he'd banged it into a door.
"Canterlot? Not? Gone? What? What...what am I DOING IN YOUR BEDROOM?", she shrieked! And covered in bandages maaaaybe just a little doped up oh wow this feels like when Flash spiked the punch at the Fall Formal...
"Why, to keep you from Auntie Celestia, of course!", and at Celestia, a stab of envy, guilt and anger raced through Sunset's head. "You ARE a wanted pony, after all. What -were- you doing in the Crystal Empire in all those horrible ruins? How DID you live through the explosion?". Blueblood's eyes seemed to bore their way into her aching skull. She could tell him everything, and then a nice little nap with her lovely Blueblood keeping her safe...
As the unicorn babbled out the story of mirror-leaping, high school domination and the final cataclysmic destruction of her teenage "kingdom", Blueblood looked up to a well-dressed unicorn butler standing at the door.
"Ambitious, willing to use anyone to get ahead, and less love in her than a starveling grub. She gives us the destruction of all these "humans" to pin on Celestia as well. You could not have done better.".
Locked in the grip of Blueblood's stare, the unicorn didn't even pause.
"All I wanted was to be the princess...", Shimmer murmured.
Malice lit in Blueblood's eyes as an idea crawled through the slimy sludge he called a brain.
"Six-seventy-five, find me someone who can paint a lovely portrait of Sunset Shimmer that I can fit in the closet."
The changeling-butler stared in confusion. "You...want her image? I can just call in a drone to copy her in every detail."
Blueblood clonked the butler gently upside his horn.
"No, Six-seventy-five. I want a lovely image of Blueblood's long-lost secret special somepony he was betrothed to wed when she came of age, but was banished by the wicked Celestia to the "humans" so that they would never know..."
And Blueblood's mouth worked hard to bring it's sarcasm into the world with the final two words....
"True love."