Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-173.80.207.170-20140122115959/@comment-90.219.4.148-20140130023340

These demons might be the tengu, looking for the person(s) who disrupted the cosmic law and order. The physical depiction is not exactly on point as in the folklore, but tengu are considered as a natural force and warriors who are very skilled at martial arts.

My other guess is that they are shinigamis looking for those who have cheated death. So probably Scott, Stiles and Allison because of the ritual that they did.