I just caught up with the latest chapter of the manga, and it left me with quite a few thoughts. My original plan was to make the "King of Angoulmois" from the Nostradamus Prophecy the Death Devil. I didn't expect Fujimoto to reveal outright in the latest chapter that the Great King of Terror was the Death Devil. So I did get it half right, but I also nearly got stabbed in the back. (When I wrote about the King of Angoulmois in Chapter 234, I intended to make the King of Angoulmois the Death Devil.)
Anyway, I feel like I should wrap this up as soon as possible, because I really can't think of how to make anything else up. This time, making shit up actually led me to stumble onto the right guess that the Nostradamus Prophecy was connected to the Death Devil, but I still didn't get it entirely right.