Most dimensions reset after a certain period of time. If there weren’t, there’d be a whole lot more lost empires sitting around.
There were, however, dimensions where they didn't reset.
For most, it seemed to just be an empty dimension. The complete lack of light in any direction certainly didn’t help to dispel that myth. However, for the very few who spent more time than reasonable sitting around recording everything, they may stumble upon the cold, frost-covered iron lumps that remained in the void.
For the Interloper, the voids became the perfect place to hide. In fact, the Eternal Forge was parked in one of these voids, pushed far enough out of the way that it would require insane amounts of luck to even stumble upon.
Which, over enough time, it had.
Within another void, the Forge warped in. The Interloper had spread a few safe houses within these voids. These were even harder to find, since they were kept unlit, powered by nothing more than a set of gravity pulleys for emergency lighting. Nothing else could last long enough for such use cases.
For the first time in eternity, there was light. A pyre, nitromethane white, burned in the darkness. An Interloper body stood in front of it, a flare in her hand. In her other, she clutched a memory chip.
“I’m sorry,” she whispered into the void. “I used you all to fool myself into believing I was leaving behind a legacy, when all I did was cast off sparks that died in the roiling seas. You tried so hard to uphold the ideals I never believed in, and died waiting for a rescue that never came.”
She glanced at the card in her grasp. "Anasi, you who loved me so, I have failed you the most.
"Next time," she growled. "I will build something that--!"
Her words choked, gasped, strangled itself in her throat. The nitromethane burned out by the time her fury had died out too, leaving only a tired emptiness behind.
“... No. If anything is to be built, it won’t be by my hands. May you be the last I failed. Goodbye, Anasi.”
A field, a sunny day, birds chirping.
Then, the space warps. A dull green deer with straw yellow hair stands up, peering at her surroundings underneath multiple layers of light cloth. There was a lazy arrogance in her posture as she stood up from her crouch. A relaxed air not from the confidence of her superiority, but indifference to life itself. She took a deep breath, and exhaled, smiling softly. Somehow, despite everything, this was the most relaxed she’d felt she could remember.
After taking a few minutes to take in the wind, the sun, the flora and fauna, she set down the dirt path. She consulted her mental map, comparing it with the small buildings coming up ahead. A few blocks down, she ran into an old, large townhouse. It was quite distinctive, especially since it had multiple branches growing out of its seams.
The Interloper chuckled. “Seems like someone has a bit of nostalgia for the classics.” Stepping forwards, she knocked on the door.
The door blasted backwards, a harried purple unicorn standing before her. “You ... you came?” she breathed.
“Of course. I promised, after all.”
They stood there for another moment, staring into each others’ eyes. The Interloper’s grin slowly grew larger and larger until Twilight squeaked.
“Sorry! Sorry,” She quickly stepped back and waved a hoof. “Please, come in.”
The Interloper squinted as her eyes adjusted to the light. The yellow jar of slime was on a counter near the door, a metal rod growing out and pulsing slowly. The rest of the area was covered in bookcases and couches.
The Interloper took one step into the house, then paused, her eyes squinting as she scanned the room. She turned her head to stare at the ceiling and groan. “I suppose I didn’t request you to enforce a complete information black-out.”
Twilight gave her an awkward chuckle, as a few hundred pairs of eyes poke themselves out from around corners, shelves, tables, couches, potted plants, stairwells, the vast amount of them being purple equines. “Sorry! Sorry. I guess I must have mentioned it a bit while at the Census, and well, you know how fast gossip goes.”
The Interloper gave them all the stink eye for one, long, sweat inducing minute. Eventually, the tension left her shoulders, and she let out a tired sigh. “Alright, let’s do this.” She looked at all of them in the eyes. “Let me be clear. This is a trial run. I’m not sure how sane of an idea this will be, but I’ve spent more lifetimes than I can count failing. Its time to try something new. So for now, I’ll introduce myself, and let y’all ask some questions. Good? Let us begin.”