A couple things. None of the Epic Level rules are in the SRD, of course, so I was somewhat limited in covering demon princes in full detail. Truth be told, I think foes like Orcus and Demogorgon are probably outside of the ability of non-Epic characters to slay. Even if that's not the case, they certainly don't make good foes for 90% of the player characters out there.
So, instead, I wrote up the princes with all sorts of information on their cults, home layers, and motivations, mixing in several adventure hooks and adding a completely new core class called the thaumaturge, who gains spellcasting power by making deals with these dark sovereigns. Some of the rituals thaumaturges need to do to get their daily allotment of spells are pretty horrific.
There are a number of demon lords (not princes) in the book, with challenge levels that make them appropriate encounters for parties of 13-25th level. The rest of the book contains the usual spread of challenge levels you've come to expect from Green Ronin monster products, plus about a half-dozen new domains (including Pleasure, Subterfuge, Pain, and Crippling) and some new spells to fill out those domains. The latter section includes such gems as "femurburst," "fit of coughing," and the soon to be world famous "phantasmal lover."
I'm really interested to see how the book goes over. I think you guys are really going to enjoy it.
--Erik Mona
