Somewhere, a conscious thought began tearing through a seemingly endless veil of darkness. It wasn't coherent, maybe even more like an instinct than a thought. It was the drive to wake up after a long slumber, the need to get up and live again.
Suddenly, the world became more than the empty dark. There was clarity, albeit only a little. Then came more thoughts, slowly but surely, consciousness was flooding into the darkness. The darkness was beginning to remember things, like who it had been before.
I am King Sombra, ruler of the Crystal Empire. The darkness declared uncertainly, though it had no mouth to say it aloud.
Sombra opened his eyes that he was suddenly aware of, and adjusted them to his surroundings.
Sombra could tell he was in some kind of dimly lit room, and once his eyes had adjusted themselves he came to the conclusion he was in some kind of a lab. All around him were glass containers, jars, test tubes, bottles, and all manner of scientific implements and tools.
Sombra found he himself was bottled up in one such container, able to somewhat make out his reflection in the glass.
Sombra saw that he was merely a small amorphous cloud of shadowy plasma, no features to speak of other than two red eyes. It strained his mind to remember what he had once been, but he could picture his former equine form. His curved horn, sharp fangs, eyes trailing dark magic, and his shadowy flowing mane and tail, all wrapped in armor and finery befitting his title.
Once Sombra's sense of self returned he started to remember what had happened to him as well.
Sombra remembered his first defeat by Celestia and Luna, the two immortal sisters being barely able to best him with their accursed jewels of power, whatever they were called. Regardless, the sisters used them to seal Sombra away, breaking his physical form down into a mass of shadow and trapping him under miles and miles of ice.
On his way into his millennial prison, Sombra had used all of his remaining power to send his empire adrift in time until he returned to reclaim it.
And return I did, only to be defeated again. I was destroyed, just as I regained my body. Sombra groaned in embarrassment.
Sombra knew the magic of the crystal heart had nearly completely obliterated him. He could vaguely remember a band of young mares, one of which being an unfamiliar pink alicorn. Accompanying them was one stallion, and a bipedal lizard of some sort. They had orchestrated his second defeat, and they were the reason he had been reduced to his current state of imprisonment.
Try as he might, Sombra found it impossible to recall anything before his stint as ruler of the Crystal Empire. He knew who he was, how to call upon his dark powers, how to drain the magic from crystals, but nothing else. Sombra's mind pulsed with discomfort when he tried to force himself to remember.
As such, Sombra was left to wonder exactly what was going to happen to him next.
Sombra's imagination was filling up with horrible ideas about what his captors had in store for him. It seemed likely they were going to try and reverse engineer his immortality, or even try and replicate his powerful magical abilities. Sombra wasn't looking forward to the experiments that he assumed lay ahead, as they were certain to be excruciatingly painful.
I may be powerless, but one day my captors will slip up. No prison can hold me forever, and I have proved myself beyond death. Sombra shall rise again.
Had he the necessary parts to laugh sinisterly Sombra would have been liable to shatter his glass prison. For the time being all Sombra could do was wait. Wait, and plan his revenge against all those that had wronged him.