If the Book of the Dead of this Subaru was truly here, then― “Am I being treated as deceased, ever since I lost my memories… The Books of the Dead of Taygeta, that Hall of Memories, is even observing the worlds I die in…?”
If that were the case, then in no way was it inconceivable that it was depicting Subaru’s Deaths in some type of form through the Book of the Dead. However, in that case, what did that make of Return by Death?
“Whether it rewinds time, or does it rebuild the world itself, I’d given a thought to both but…”
For argument’s sake, along the hypothesis that the Books of the Dead held a method to generate the Book of “Natsuki Subaru”, it could not be helped but to reach the conviction that the latter had much more likelihood. If that held true, then the phenomenon which encased this Natsuki Subaru was not something as charming as Return by Death, but― “Am I an idiot? No, I am definitely an idiot… Damn coward.” —Re:Zero Arc 6, Chapter 73, ""Natsuki Subaru""