User blog comment:Chaos11394/Any Ideas for new villians for future seasons!/@comment-1509826-20120716215113

Nephilim, hybrid of man and angel, unholy creatures, that were created when rogue angels, raped several human females, thus causing there Nephilim to be created, they are giant horrible behemoths, that posses angelic powers, and destroy all that gets in the path, so dangerous that god personally destroyed every last one of them.

How they return is up to you.