Gilgamesh and Hercules could be the same account for example. The Norse, Egyptian, Greek, and Indian gods are the same beings just tailored to that specific culture.

The Dead Sea scrolls and the book of Genesis seem to suggest that these other gods and Demi gods are actually the devil's fallen comrades and they largely destroyed themselves in a civil war e.g. Clash of the titans or ragnarok. The Vedas have a similar story as well.