These notes refer to the story Elements of Opposition, specifically chapters 7 and 8.
I mentioned earlier that with Chapter 7, I would post a "what has gone before" synopsis to catch everyone up given how long it's been since the story started, which would also enable those who skipped Chapters 4 and 6 due to the content to be able to read the rest of the story, so here it is. Because it's very long, I put it in a blog post on Fimfiction rather than trying to include it at the start of this chapter.
Pinkie's song is based on "Hush-A-Bye" by Peter, Paul and Mary. The original words were "Hush-a-bye, don't you cry, go to sleep you little baby. When you wake you shall have all the pretty little horsies."
The stuff with Pinkie's identities was from "All Apologies", the second chapter of Awkward Conversations, which I never finished and therefore you haven't read it. The short form is: Pinkie does not have Multiple Identity Disorder, and Pinkamena is not a psycho killer, but I am playing with the concept of Pinkie and Pinkamena as separate personalities, if possibly not full, individuated personalities. Pinkie personifies parts of herself that her own consciousness would interfere with -- for example, her giddy behavior and easy distractability should work against her ability to manage logistics for party planning, so she made the part of herself that can do logistics a separate persona so it wouldn't interfere with her basic personality, and outsources the work to that part of herself so it doesn't interfere with the Pinkie consciousness. This is actually a lot like what all of us do, except that when we hand tasks over to the part of our brain that does that task and get our consciousness out of it, we neither personify that part of our selves nor can we clearly receive communication from it. I'll go into this more in a blog post eventually, and also, finish All Apologies. Point is, this is not the usual fannish take on Pinkamena, or for that matter Pinkie.
A Changeling Princess is a biological Queen who has not fully matured; they don't reach full maturation as Queens unless they have their own Hive. They are much more powerful than most Changelings, but not as powerful as the Queen is. Eventually I'll go into some detail on my take on Changelings, but all you need to know right now is I AM TOTALLY IGNORING THE COMICS BECAUSE THEIR VERSION OF CHANGELINGS IS UTTERLY STUPID. I consider comic books optional canon, and right now I am totally exercising my option out.
Dammit, I could have sworn Cadance's cutie mark was also on the Tree! But when I rewatched the scenes with it, it wasn't there... Well, it's there now, just on the side where you can't normally see it when you face the Tree.
There is no actual rape or physical abuse in this chapter, but there is discussion of it.
While I took from the comics the concept that the Nightmare Entities are real, the comics' portrayal of them is entirely too silly and childish for my tastes. My ideas regarding what they are are influenced by Jordan179, by Egyptian mythology, and by the work of Charles Stross in his Laundry series, itself based on Lovecraft's Cthulhu mythos. Also, windigos.
The crystal solution is partially inspired by C-Puff's Virus.