it's important to not confuse the Nephilim with the Watchers.

the Nephilim were hybrid human women and demons for the race Watchers. These Watchers were originally created to watch over mankind but they took a radical left turn.

after the flood, no more hybridization possible between demons and physical humans. however, possession is the new hybridization.

and, scripture tells us no more destruction by water. next time, by fire.

interesting stuff Unc.
i will have to read and absorb all of that for a bit to take it in.