Great show guys & wanted to share some thoughts which you may or may not have read.
*For Mordiggian, whom I've not yet encountered in a game, sounds a lot like the people who wrote the Dr. Who episode "Silence in the library" got some shared fictional DNA in between that show & Mordiggian.
*Azathoth & your descriptions if it was around in cult form reminded me a lot of Roger Corman's "Masque of the Red Death" film at the end. Oh and as for the other ideas on Azathoth, listen to the following bit of Role Playing Public Radio with Tom Church's scenario Divine Fire (link goes to part 1 & then part 2). http://actualplay.roleplayingpublicradio.com/2011/01/systems/call-of-cthulhu/call-of-cthulhu-divine-fire-the-kgb-files-part-1/http://actualplay.roleplayingpublicradio.com/2011/01/systems/call-of-cthulhu/call-of-cthulhu-divine-fire-%E2%80%93-the-kgb-files-part-2/
*Nyarlathotep - I also like the small cameo I believe he has in one of the core scenarios in the 6th ed book (Dead Man's Stomp)
. Am I the only one thinking of Nyarlathotep when watching the 1990s horror film with Christopher Lee "Funny Man"?
*Shub-Niggurath - very fun & love the idea of the alien paradise or circus, easy to throw in something with the 'milk' (used heavily in the Age of Cthulhu scenario) or going into the Ken Writes about Stuff issue of the Dark Young to throw in all kinds of natural oddities or make up your own like using all cactus or seaweed for one.
*Yog-Sothoth - just will point to the one fun one in the Secrets of San Fransisco book that has one featuring dear Yog
*Cthulhu - want to say in the old book found recently (Cthulhu Now from Chaosium) there are some pretty wild scenarios plus a great little bit of research on forensics from Victorian times to now worth reading (will have to raid the references for it & put here later for all to research & enjoy), anyway one scenario in there is using the big C & it's dreams that many might not have tried & looked like it could easily send it back to the 1950s or earlier with more fantastic technology
* Bast - I'll have to look up her with Bloch as I must have missed those but she's a favorite here with me, even got one scenario somewhat written as an introductory scenario but fell a little flat that has a fun moment I'll find a way to put into another scenario using a small cult of Bast. Also Call of Cathulhu is out there & some actual plays on Role Playing Public Radio where you might run into Bast more while playing curious cats.
* Hastur is one of the near favorites here until reading 'Soldiers of Pen & Ink' for Trail of Cthulhu. You want to throw the mythos into something wild & chaotic? How about the Spanish civil war? Also not going to spoil it more but you not only can meet Hemmingway but a chance to recruit him to help is quite a fun note in that one. Plus also in Trail is the Repairer of Reputations scenario too I have yet to read but should be quite a treat.