More from reading tons of ancient/hidden history stuff - I'd cite Zecharia Sitchin as the prime inspiration for that term.
Writing my own fictions (more a pulp style universe) but the "Sword and Sorcery" character (think Conan except not Conan) is set in the Antediluvian era so did a lot of research on this - found these incredible illustrations that are far better than anything I could do. I'm envisioning an ancient - now forgotten era - tens of thousands of years old - essentially 100,000 years to 1 million years from when man was created and quickly fell, then the time the watchers grew bored/defiant just watching him struggle in the wilderness and gave man technology, civilization - but they were wrong and their gifts only made things worse as man was still with sin - leading to a war between giants (Nephilim) and their parents - Book of Enoch/Titanomachy... This then led to a degrading period of the ancient empires and man's increasing wickedness, before the Deluge.
Tempted to ask (or rather Comission) him to do "Afire-With-Love" a character of mine for those stories, but probably be too expensive (worth it) and confuse people since he's doing real (well real legendary at least) characters... Put a link to some sketches.