“The remainder were killed off in ancient days one by one (the giants of the bible, etc).”
There were no remainders of Giants from before the flood, they would have had to come from Noah’s sons and their progeny. I have read some fascinating stuff about archeaological discoveries made concerning the peoples(giants) that the Hebrews eventually destroyed when they finally took Israel. Satan’s genetic manipulation via the Nephilim may have yet been at work even this late in human History.
Noting that Christ said that the days of “the coming of the son of Man” would be as the “days of Noah”, reading up on what made those days so evil, part of the blame is assigned to the Nephilim. Now in the past 60 years or so, there has been marked increase in the interest in the possible existence of ET’s. Professional psychologists are studying and documenting increasing frequency of reported abductions and visitations. Have the Nephilim descended again? Have Satan and his minions been finally thrust out of heaven? I’m asking posing questions only. Does Christ’s analogy of the Days of the Coming of the Son of Man match that of the Days of Noah exactly, including the arrival of the Nephilim?
You are discounting the fact that Noah’s family may have been carrying recessive genes.
Noah was righteous. He saved his family. HIs family could have included someone passing the corrupted genes.