I know I should wait for translation, but is this thing Yuugi is talking to one of the heads of Orochi? And maybe Yuugi is a fraction of Orochi's power?
It did battle with the gods, gripping the world in chaos and fear.
In the age of legend, there was an enormous snake spanning over eight mountains in size.
was called Yamata-no-Orochi.
That giant snake
It dove into the earth, created this cavern, and lay here for thousands of years.