User blog comment:Noctosphere/We finally get a Human as a big bad. Your thought?/@comment-5583089-20160601215732

The Stynes... they where a major antagonist of season 10, the nearest we have had to human Big bad's...they seem to be the evil men of letters... i think the stynes could return in season 12 along with the men of letters as main antagonists, but the MOL later realise the winchesters actions are justified and they team up.

Theres also Rowena...a witch is still a human, and she could also play a wild card factor in season 12.