Demetrios1453
Legend
I'm going to be so happy when I get this book. The Sibriex gives 5e an Obyrith presence (and the Obyrith element of Abyssal history was easily the best part of the first Fiendish Codex), getting some demon lords and archdevils put in one central place is always nice, I'll always take any new Gith stuff I can get, and the Cadaver Collector is my favorite construct. This might be my favorite supplement overall for the edition.
I imagine we're going to get more Obyriths besides the Sibirex, since, going by the pages we've seen in the previews already, we're very likely to get lots of devils and demons. I'll repost something I said in the "Mordenkainen's starting to show up in the wild" thread concerning the pages and why we'll see lots of fiends in it:
"Moloch is in the "D" section (for "Devil" obviously, and the "D" is helpfully shown on each page), and is on pages 176 - 177. I hadn't looked previously for some reason (which is odd, since I always check for page numbers in previews so I can get as much info as possible on what an upcoming book contains), but the Astral Dreadnought is on page 117. So, given that we'll likely have a few "A" creatures before the Astral Dreadnought, the Bestiary is going to start somewhere around page 105 - 110 or so. As we know the book is 256 pages long, and the Bestiary is the last chapter of the book, that will give us ~155 - 160 pages or so of monsters, which is pretty impressive (barring a surprise appendix or something similar). Also, that means it's going to take a full 60 pages or so to get just from towards the end of "A" to the middle of "D". As we already know from the Fantasy Grounds preview that there are not that many "B" monsters (and even most of those there will actually be in the Demon and Devil sections in MToF), either we have a lot of stuff for "C" (while we know some clockwork stuff is going to be in there, it's probably not going to be dozens of pages worth!), or we're getting a heck of a lot of demons and devils (duergar will be after Moloch, and drow will be too, although they will probably be in the "E" section anyway like they were in the MM). Even the reprinted demon princes from OotA only take up 18 pages. Besides demons and devils, the only "theme" creatures that fit in that range would be derro, and I can't see them taking up more than a few pages. And of course, we'll still have other random creatures in that section as well. But still, that's a lot of page acreage to fill in such a small part of the alphabet! (And, we'll still have ~90 pages of monsters left for the post-Moloch section as well!)"