Project NEMESIS

This spell requires total darkness and a room, or cave, at least 30 feet below ground. The ritualist(s) need to pour one gallon of human blood in a black marble container which also contains some pulverized lava stone and part of a root from an ancient oak (at least 100 years). 

This ritual is a left-over from the titanic wars between the Great Race of Yith and the Flying Polyps. No record exists of it in writing but occasionally a Yithian Memory Crystal is unearthed that contains the instructions. The ritualist need six rock crystals (approximately 1 foot long) inscribed with hyper-dimensional symbols fixed to a complicated three foot high metal structure (somewhat resembling a silvery centipede curled around an umbrella) made out of a precise mixture of Silver and Scandium. 

Some questions to help you come up with your own version of the Cthulhu Mythos. 

You need some fresh inspiration for your horror scenarios? Then just go back to the source, but not all the source. Let's take just one story, the Dunwich Horror, and use it in isolation from the other stories as inspiration. 

We are, as a race, completely and utterly mad. Born into the world screaming and insane, we are raised and civilized, our bodies and minds carefully shielding themselves, adapting themselves to a life that we can tolerate.

Just meeting a Shoggoth is not in itself horrific. Rather, it is a question of placement. The key to good mythos horror is to take the familiar and and introduce the terrifying into the familiar in a shocking way: things not working as they should, places being where they aren't supposed to be, and things challenging your assumptions about how the world/your body/science/religion etc. should work. 

I want to use Nodens in an upcoming game of mine, but want to make him an interesting and more appropriate part of the Mythos. My main goal is to surprise my players with a re-interpretation of an old standby. Since Nodens is the one part of the Mythos that I absolutely detest, I thought he would be the best target.