Which religion began the myth they all refer to?

Separating a solution into two problems: I combine the idea of Leviathan, beast of the Deep in Judaism; Tiamat, giant serpent whose body became the sea and sky in Sumerian myth; Elder Gods forecast to return and end humanity in Cthulhu; the endless cycle between Shiva and Vishnu in Hinduism; and the Midgaard Serpent forecast to return for Ragnarok in Norse myth into one comparative religious idea. I feel very gnostic when I say that deep down all of these are ways of expressing that people know what the Big Bang is, and that the resulting expansion of the universe is ultimately finite. Perhaps I just exemplified the failing point of comparative religion in believing that my Hindu science theory of calpas is the correct one, and all others just copies. I think these are also ways of remembering that life has ups and downs, bright days and dark days. I think it says, in my agnostic thinking, that what makes or breaks your day is often beyond your awareness or even comprehension.
Listening to heavy metal and reading mythology after taking Ginkgo Biloba is a mind-expanding experience.