A changeling, silent and hungry, barely managed a stagger through the forest as green ichor oozed down his ravaged legs. He was the last of his kind left in equestria after their mass expulsion from Canterlot, and he knew it. He couldn't sense any others of his kind for miles... Though perhaps that could be accounted for by the loss of his connection to the hive mind of the Swarm, his Queen... But that feeling of loneliness was enough to convince him as he trekked through the middle of a dark, forboding forest, wounded and starving.
He had no way of knowing how long the blast knocked me out, but, luckily for him, changelings heal quickly from most anything, given the energy and rest. Unfortunately, it felt like days since he'd "eaten" the affection of an intelligent being, so he was struggling to barely walk, and there was no where safe to rest... not in this unnatural forest. Even one who'd never seen it or heard its name, such as he, could tell that much.
He attempted to navigate his way out of that foreboding forest... and failed. More than once did he find himself at a swirling pool of water, clean and clear in the sunlight. Despite the growing frustration he felt, each time he found the pool, he couldn't help but smile. Smile at his secret from his kind, exposed to the daylight. He was slightly different in appearance from the uniformity changelings, and always had to hide it. He had a long, especially ragged blue mane, and his tail dragged upon the ground if he didn't bind it properly, despite the fact that he was near twice as tall as all but his half-sister, the Queen.
One might ask what that made him, given the chance. A king? Prince? Noble? No. There is only the Queen and her Swarm. Their mother was a mare, now long since passed, and their fathers two of the many non-nondescript faces among the changeling swarm. Young Queen Chrysalis took the place of the prior queen when she could no longer take care of the swarm, and her brother, ever playing the role of the servant, simply assisted her as her subject most of the time... and as her brother when no one was watching.
She never let down her guard, but he knew that her simple knowing he was there helped his queen some inane way... Kept her more or less sane, kept her priorities straight as she scoured the globe for a place to feed her swarm. When the changelings found Equestria, she told her half brother a little of her plan, then set to it with not a word more. She handled it all, and as soon as we felt all that love practically bursting from inside the magic bubble that was Canterlot...
Well... the rest is history... suffice to say that her plan failed, and resulted in the changeling's abrupt and unceremonious ejection, flinging all... most of them clear out of Equestria's borders, probably killing them.
After wandering in random directions away from that pool's mixed blessings, the changeling eventually found something different from the dark trees all around... Not the borders, mind, but some sign of civilization... a small hovel. He stayed back for a time, merely watching the hovel and its dark-coated inhabitant from a distance, before his hunger began to overtake his judgement.
There is one other difference between the changeling "prince" and the rest of his kind, other than appearance... his ability to transform. Most changelings can't transform into something or somepony they haven't seen at least once. They need a picture, or to see the victim of their impersonation at some point before taking their form. He, on the other hoof, could take any form he wished, real or imagined. When he and his sister were younger, she had once said this was because she'd peered into his mind, and seen that his imagination was the best among all the Changelings... and that it was a double edged sword.
Changelings, ironically, don't take well to cultural changes. The ideas of the young changeling "prince" from his early childhood would have caused civil disturbance aplenty, decimating their numbers. But now, he realized with a smirk, he could utilize his full power without fear of one of his kin noticing. He checked to see if anypony or anything else was watching him, then closed his eyes and considered for a moment the form he wanted to take.
He decided a few simpler alterations would be the best option... He chose to shrink his imposing height a bit so that he didn't look like Canterlot royalty, though not so much as to look absolutely common. Next, he mentally repaired his naturally tattered body, minus the wounds, and gave himself a coat of shining black... no, dusty brown hair. He did the same for his mane and tail, shortening them to lengths more proportionate to his new size. Last, he chose to become a unicorn, and gave hinself a cutie mark and an appropriate name: A mysterious rune on a twisting, curved background for the colt, Rune Script.
He hesitated before continuing the changes to his form, thinking the disguise too obvious, as a swarm could often be identified by the colors of their eyes and manes. Too tired to come up with something completely different, he simply decided to swap the colors for his coat and his mane, then used much of his remaining energy to transform himself. He then rubbed a bit of dirt into his messy coat, and began limping towards the mare's house.
The changeling reached for the door and knocked feebly, then sagged one shoulder as though it was hurt... which, actually, it was, though he normally hid it far better. Still, he slumped tiredly to the ground, cursing the weakness of his body for a moment before forcing his mind to the task at hand: being an injured pony.