The only person that I know about who noticed the problems with Torah scholars that are demons is Rav Nahman of Breslov. You would think that this ought to be well known. And also a well developed subject. But for some reason the whole idea seems to be ignored.
[Though you certainly find this in the Mishna and Gemara, still the subject seems to be unpopular].
In Rav Nahman the subject is brought up (LeM I:12 I:28 I:60 II:8 and lots of other places I forget off hand.] but without going into the subject in such a way that can give a person tools to discern.]
In tractate Shabat the sages said "If you see a generation in which troubles are coming upon then check the judges of Israel;-- for all troubles that come into the world only come because of the judges of Israel." [I forget the exact page number but it is towards the end.] The Mishna in Avoda Zara says that "The Prushim are the destroyers of the world". [ פרושים הם מכלה עולם].
[Though you certainly find this in the Mishna and Gemara, still the subject seems to be unpopular].
In Rav Nahman the subject is brought up (LeM I:12 I:28 I:60 II:8 and lots of other places I forget off hand.] but without going into the subject in such a way that can give a person tools to discern.]
In tractate Shabat the sages said "If you see a generation in which troubles are coming upon then check the judges of Israel;-- for all troubles that come into the world only come because of the judges of Israel." [I forget the exact page number but it is towards the end.] The Mishna in Avoda Zara says that "The Prushim are the destroyers of the world". [ פרושים הם מכלה עולם].