"We still deal with these beings today..."
I don't think so. If what you say is true, they would had to have been on Noah's ark and in Noah's family.
Another thing, if it was God's intension to intervene, and remove these people from humanity, then they no longer exist.
I guess I wasn't very clear what meant about that. I was not saying that we still still deal with the procreation and offspring of these beings, but we do still deal with supernatural mischief. The source is the same in my opinion.