Overall, it's very difficult to describe it in words, not least because of the unusual nature of what was happening, but also because of my not-so-rich vocabulary and rather meager literary skills, and of course, because many details, as always, elude me after waking up.
Anyway, the point is that I had some kind of problem with my head (lol) – something like a split personality, only it wasn't expressed quite as it should have been. We could communicate and so on, and this half apparently considered itself a girl, was incredibly evil by nature towards everything around her, and possessed psychic abilities capable of tearing reality apart. This part of the dream was extremely creepy but still incredibly interesting.
Then, at some point, this other half of mine "split off" from me and became a person – something like my sister. I don't remember what she looked like, but I can say for sure that she had black hair, probably because of the association with the initial "darkness" and "evil" that this personality represented. For some reason, we were then sent to study at a military academy, where we didn't get along with our "comrades." Apparently, they took us for freaks and didn't like that we were flirting with each other in "class." Nevertheless, possessing the aforementioned abilities (which I now also had), we had no trouble dealing with all the pranks they pulled on us. And we were, in general, doing well together – we didn't care about the opinions of others, and they couldn't do anything to us. There were many pleasant and interesting things, but I don't remember the details after waking up. At the end of the dream, there was perhaps the funniest part (of course, it wasn't funny in the dream itself – adrenaline and action): I was fighting some guy in the air (not on planes or jetpacks, but just in the air), and the whole battle was very anime-like, and in the end, I snatched his sword and stabbed him once in the throat and once in the stomach. That's where the dream ended.
I don't even know what this might say about me as a person... But in general, I liked the dream, both in terms of content and concept. Ah, what could be better than two people who know everything about each other and accept each other for who they are... What could be more romantic...