What do you think about merging Harry Potter universe and the Cthulhu Mythos universe?
IMO Mythos spells (the one that make you insane for 24h, or kills you by making you burn from inside - you burst in ball of flames) and book's (Necronomicon, Liber Ivonis, Unausprechlichen Kulten, De Vermis Misteriis and others). Heck. In the Cthulhu Mythos their is better ways to maintain immortality than some stupid horcuxe's (swap souls and other fun stuff). Also what do you think about making Harry a member of some sort of cult of Great Old Ones (King in Yellow, Cthulhu) or Outer Gods (Nyarlathotep, Yog-Sothoth or Azathoth). That would provide a nice edge for insane!Harry stories.
Recently I am using a Mythos cult in my story. In my story Lily is worshiper of Lilith - an Elder God of sex and reproduction. She (Lily) finds out that James is cheating on her so she summon the Hound of Tindalos (or it could be a Star Vampire - they are invisible and they are giggling all the time, when one of their tentacles start to suck your blood out; also they are immortal) to kill James in the middle of Diagon Alley.

(sorry for all my grammar mistakes)

 

Probably wrong board and I have never heard of this... series/book/game.

 

The Cthulthu Mythos is a large grouping of short horror fictions inspired by an Author named HP Lovecraft. The Mythos grew very large, and if you look for it, you can find many books, none of which have the same stories. That said, the idea is intriguing, but I doubt any but the most experienced and skilled of writers could pull it off believably, let alone while retaining the feel of the tales of the Cthulhu Mythos.

 

It's possible, but it would have to make the Potterverse a great deal darker than it currently is. Vorlon666 works in some of the mythology from the Simon Necronomicon (The bits with Tiamat, who is in no way, shape, or form Egyptian, despite the strong Egyptian flavor of the story). It would make a good dark!Harry story for him to witness a ritual by a cult of the Elder Gods, much like the "Mad Arab" is said to have done. Actually, a book was recently released by "Simon" (The guy who published the most popular Necronomicon) that details his story of the discovery and history of his involvement with the book. I picked it up the other day, but haven't read it yet. I'm almost certain the book is a forgery, but it's also excellent in its own right, ignoring issues of historical validity.

 

I could actually see a story something like Evil be thou my Good by Ruskbyte now that I think of it. It would also likely be a good setting for insane!Harry, but of a more intelligent sort that what I have read of that genre.

 

It all depends on the sort of Cthulhu mythos story you prefer. It could be "classical" Lovecraft/Derleth-type of story ("The Lurker on the thresold"), it could be Brian Lumley viev on the Mythos (good Elder Gods fighting with the evil Great Old Ones and Outer Gods; humans can destroy creatures from the Mythos) or it could be an RPG view on the mythology (action/adventure/horror-story - based on "Masks of Nyarlathotep" and "Horror on the Orient Express").