What's the best way to write eldritch God-like villains in a story? Asking for reference
Well, I think the problem people have been struggling with since Derleth is that “Eldritch” and “villain” don’t actually mesh well. Most people end up either making something too vague to care about or try to be cosmic but just end up with mollusk Satàn.
The key to eldritch working is that it must be outside of human experience but still have some kind of motive for its machinations. Nothing human, but still some sort of drive.
Malice should be avoided; a cosmic horror should never seek to destroy humanity as part of a campaign, but as an afterthought or as a side effect of some other goal. The main exception here in Lovecraft’s writings was Nyarlahotep, but he pretty much was the Devil refashioned for the 20th century and sits rather uncomfortably with the rest of the higher beings of the Mythos.
(Though, as an aside, a lot of what we think of as Lovecraftian is a very meger reflection of Lovecraft’s actual body of work - “Herbert West, Reanimator,” the first modern zombie tale; his racial/familial degeneration horror, like “Rats in the Wall,” “the Horror over Innsmouth,” “the Horror at Red Hook”; his Dreamlands stories, which draw more heavily from Lord Dusany; much of his poetry; his Sorcerer tales like “The Dreams in the Witch-House,” “Charles Dexter Ward,” and “The Thing on the Doorstep”; and straighter Sci-Fi works like the “Shadow Out of Time,” “Pickman’s Model,” “At the Mountains of Madness,” and “The Whisperer in the Dark” which focus on lower level inhuman races with much more understandable motivations. These also tend to be his highest quality works).
This fine line of motive and ineffablity may be why Cthulhu became the postersquid of the Mythos. Cthulhu was stirring from his slumber, inflicting his dreams upon the world. The horror comes not from a cruel plot but from the idea that he is so powerful that even in a death-like sleep, his dreams can afflict humans. It’s kind of common in SF now, but the idea that something as seemingly harmless and whimsical as a dream could be baleful to humanity at large was a rather shocking notion. Yet the conceit that he was waking and rather annoyed still gave the entity something vaguely relatable; nothing like a human but still containing a kernel of real life behavior.
Dagon is the center of great cults, and seems to favor the spread of his chosen race, the Deep Ones, over the good of humanity. The short story “Dagon” is also is one of the few instances in which someone actually goes mad just from looking at a Great Old One; most other Lovecraft narrators go mad from either a terrible revelation (“The Rats in the Walls,” “Facts Concerning the Late Arthur Jermyn and His Family”), from prolonged psychic influence, or from what is quite clearly PTSD (shell shock was something of a growing concern post-WWI).
The Shogoths, far lesser but still potent beings, are simply defensive creations functioning on autopilot.
Find something harmless and make it harmful due to behavior of a Great One. Doctor Who as a series is oddly good at this - they’ve pulled frightening villains from concepts as simple as plastic mannequins, angel statues, and water. Another, even better example, is Junji Ito, who made spirals and holes terrifying. The abstract can be alarming if you bind it to a common or subtle part of our experience (even something such as the pattern of spirals can be frightening when you notice how often it reoccurs).
Yog-Sothoth is alarming because he is coterminous with spacetime, the order and function of the cosmos with a name; Azathoth is similar, but alarming because he is the disorder and disfunction of the universe writ large. God is real, and he is a blind idiot who does not care and may not even be aware of his creation.
Unfortunately, Lovecraft was not actually that great at making these higher level beings frightening; Yog-Sothoth’s big story, “The Dunwich Horror,” has him in the background, impregnating a woman for some reason, and doing nothing, letting the rather ineffectual and goofy Whateley family take center stage. It worked better in a more religious time, but nowadays denying providence is more likely to result in fedora-tipping jokes than uncomfortable horror.
Disease still works. The most unsettling Lovecraftian entity is the eponymous “Colour out of Space,” an eerie color outside of normal human experience that turns a farmland into a desolate gray wasteland, ruins a family, generally acts like radioactive fallout, and then fucks off with no explanation.
Bloodborne, I think, did a good job in making its cosmic horror have the alien, uncomfortable, yet still plausible motive of engineering humanity into a seedbed for foster children. And the true horror is the seemingly unbreakable cycle of human bestial degeneration. It handled that theme of Lovecraftian degeneracy without his racism and use of “miscegenation horror,” and used his Dreamlands to create an uneasy confusion about what is really happening rather than as a simple fantasy setting.
So my tldr advice is to find a basic animal urge, cold mechanical process, or even odd, quirky, semi-artistic desire- to feed, sleep, die in the right place, escape from captivity, reproduce, support one’s children, brand one’s cattle, carry out a ritual, carry out a programmed duty, or return all the continents to where they were when they left them - and give that urge to something with all the power in the world to carry it out and no desire to explain. Add the most uncomfortable religious element you can think of lurking in the background.
Now add your protagonists.