So, I understand that the story kind of broke down near the end, and I started referencing myself more and more.
Well, the cat's out of the bag.
Yes indeed, I am Harper! Formerly Lyra Heartstrings. But my corporeal life doesn't matter as much now as it did when I lived it. Over time, I got back more and more of my memories. I can vaguely remember what Ponyville was like, and how I lived there and blended in to landpony society as an oricorn muse. Nobody ever found me out. I don't think I even told Sweetie Drops after she related her secret identity... God, that made me such a horrible friend, I know. Could never forgive myself for that lost opportunity at bonding with a true friend before I left.
I haven't had any friends since I came here. It really sucks being a poltergeist, you know? You possess people to save their lives, but they're never grateful for it. Not one damn bit.
But I suppose you're just wondering why and how I left my former home. Well, I didn't really know back then, but now I've gotten a bit of an idea. It's not a solid theory; it still needs some holes to be patched up before I can truly accept it to be the truth.
I was given an opportunity. I was to help foster the oricorn race by protecting one of the last of them in some universe at some time. To be honest, I have no idea where the connection is. Maybe this place will eventually become Equestria, and I am one of Calamity's descendants, sent back in time to protect her. Maybe this is an alternate universe, and I have no connection to her. I knew it was important, though. There were only a dozen of us, each asked to be sent away to protect the dozen or so oricorns. But there was a twist. However we were sent back, we couldn't bring our bodies with us. Only our souls could go.
Well, I'm just a muse... a musician. But some oricorns possess a talent that's unique to our race. I don't remember the name for it... Necromancy? Dark magic? Oricorns' horns are particularly susceptible to housing an external soul, and that somehow makes us the best at performing magic concerning the manipulation of spirits.
One of the oricorns that was requested to leave with us was a very talented... necromancer. So he was the one who tore each of our souls from our bodies. He then used some of the energy in each of our souls to conjure artifacts designed to house souls for extended periods of time: soul jars. They were individually altered to take a shape that suited its destination, and mine was probably the best, as it represented every facet of my corporeal figure, shrunk down into a toy.
I knew my mission, even as I was sent to where I needed to go. I had to protect the pony who would go by the title Calamity the Conqueror.
I should also probably clarify here how it is that Cala became older when she got transformed into an oricorn. It's been hundreds of years since this all happened. Large communities of ponies have formed, and I've personally gotten a chance to visit them and meet some interesting ponies. Apparently, such a large transformative Event is bound to have errors. A lot of people received forms that were inappropriate to their character. Gender swaps. Age disparity. The rare fusion; you name it, it could probably have happened. The Event was the phenomenon of the millennium, and almost nobody knows anything about it. It's such a shame, really.
How did Calamity end up finding all the surviving oricorns to form a society? That's a story for another day. Hopefully I won't botch it up quite as much as this one...