Cute, but if people are going to do this kind of thing they should understand the source material better.
It's been a while, but an important thing to understand is that Cthulhu is not a god, he's a space Alien. He happens to be the High Priest of the great old ones, NOT one of them himself, despite being gigantic and very powerful.
A simple version is that basically what happened was that Cthulhu and his race (giant creatures like him) arrived on Earth and established an empire. Humans were his slaves and were brought with his people from the stars. The most direct descendants of that culture being detailed in the short story "The Mound" which was actually only edited by Lovecraft. Those humans having powers like eye to eye telepathy, intangibility, and the abillity to animate the dead as zombies, which other humans had lost touch with, including those who continued to worship The Old Ones, or plotted to bring about the return of their masters.
The actual native life form of Earth was these cone-headed things which had been possesed by the Yithians who were entities who engaged in psionic, possession-based time travel. These possesed creatures built a civilization on Earth and Cthulhu basically tried to conquer it, only to fail after a great war where he was cast down and imprisonened, and saw his gods effectively banished and their places of powers locked away by "The Great Race Of Yith". These is where the "elder seals" and such come from. The Yithians themselves however ran into a nasty creature referred to as a "Flying Polyup" which they wound up in a war with, their interest in earth being minimal at that point having finished their research they simply returned their minds back to their place of origin and left the lobotomized cone-headed aliens to fend for themselves. This lead to their civlization being wiped out entirely virtually overnight and the Polyups going into a deep slumber.
With all the big players gone the abandoned humans who were viewed as little more than clever animals and slaves effectively inherited the planet and began to develop their own civilization.
This isn't even getting into concepts like the Mi-Go/Fungi from Yuggoth and the like.
Yes, I know I probably have a lot of this wrong since it's been a while, but one of the problems with most people who mention the Mythos is that despite what cultists in various stories might think, Cthulhu is not an end game himself. Generally speaking if he was ever awakened he would then restore the worship of his own deities and return humans to being slaves and cattle.
It's also noteworthy that The Mythos was written from the perspective that humanity peaked back in the 1920s and we would never develop better technology than what we had then. Our own weakness and irrelevency being a big part of the theme. Despite what companies like Chaosium have written in their books and games, if one was to nuke Cthulhu he would die instantly, not "reform 15 minutes later, radioactive and mad". By the original concept technology like we have today could not exist, we technically have weapons that are far superior to what the Yithians posssed.
Still, that point aside, the basic idea of the Mythos is that we had super races in the ancient past fighting eath other. Space aliens with magic and horrible gods, and transdimensional/trans temporal aliens with super science. The war ended, but millions of years later the seals on the remnants of the losing faction are failing and us, totally irrelevent humans, are inevitably going to see our civilization and freedom fall to something far greater than ourselves, which sees us as nothing more than cattle.