YMMV / Praefacio Of Blue

• It Was His Sled:
  • The fact that Kyle's mother Prim is a rampant psychopath who jump-started Riliane's possession and had Kyle possessed twice, among other heinous acts is so widely spread that almost no one in the fandom treats it as a spoiler anymore. Still, in the series itself it was a bit of a mystery whether she was really responsible for all that or if Abyss I.R. was pulling strings behind her back.
  • The reveal that Abyss I.R. is not the old woman at all but rather the cat that's always on her shoulder is accepted as common knowledge by the fanbase at this point, despite being a pretty shocking spoiler at the time.
• Jerkass Woobie: This novel makes one out of Ney Phutapie, who was unloved and experimented on since birth, used and emotionally neglected until her sanity completely eroded away. There's a brief period where the audience gets to see her as Gretel, and remorseful for everything she did.
• Memetic Mutation: Fans who read this book (or heard about it from said fans) became prone to making comments that go "CURSE YOU PRIM MARLON!"