I've discovered some more Touhou music I like. These can all be accessed from tvtropes' Touhou music page, so I won't link them.
Pray, by IOSYS. It's a remix of Sanae's theme. It's very beautiful. It might make you cry.
Floating Darkness, by TatashMusicCircle. It's a remix of Nue's theme. It's the kind of rock that makes you grin in an evil manner and say, "Exactly as . . ." you know where I'm going with this.
Poltergeist 東方, by おるたねーと. It's a remix of Kana's theme. I love Kana's theme, it being one of the best Touhou pieces ever, not just from the PC-98 era. This remix really does the original justice. Beautiful, sad, and happy, all at once. You may need a tissue. (And yes, Kana will appear in Mentor and Protege. I guarantee that.)
There's a video out there that uses a techno remix of Bad Apple for its music. I love that video; the animation looks like something out of a Final Fantasy cutscene, even though it's only in black and white. Be sure to watch the Megpoid version, too!
EX Devil's Rush (Road of Pandemonium). It's a remix of Rumia's theme. I don't really like the original theme of Rumia, but I sure like this version! It rocks.
And there's just so many more! Also, I have an update; I have been writing more Mentor and Protege recently. I have a deadline: chapter 5 will be uploaded on or before Thanksgiving, of this year. Look forward to it.