Letzim - scorners - also connotes forces of impurity, so perhaps Chazal felt that these forces can project out or come about by partaking in Greek culture and art and render people tamei or harm them or just be bad influences in general. Here is T. Zohar 27:2 referring to forces of impurity and people of the Erev Rav, in commenting on the letzim in Psalm 1:1:
"Who merits to ascend there, who did not walk in the counsel of the wicked, for she (it) is evil counsel from the side of the Tree of Knowledge that is good mixed with bad. 'And in the seat of scoffers, he did not sit.' Who is the seat of scoffers? This is Lilith, the mother of the Erev Rav, for she contaminates like a menstruated woman by her sitting; so too do the Erev Rav contaminate by their sitting, the righteous who sit among them, as doth a niddah."
מאן זכי לאעלא תמן, אשר לא הלך בעצת רשעים, דאיהי עצה בישא מסטרא דעץ הדעת טוב ורע, ובדרך חטאים לא עמד, מאן דרך חטאים ההיא דאתמר בה כן דרך אשה מנאפת, אכלה ומחתה פיה וגומר, ובמושב לצים לא ישב, מאן מושב לצים, דא לילי"ת אימן דערב רב, דאיהי מטמאה כנדה במושבה, וכן ערב רב מטמאין במושבם לצדיקיא דיתבין בינייהו כנדה:
Leitzim also refers to "demonic tricksters" for example in Rabbi Nachman's Sipurei Maasiyot (Story Tales) - Appendix of additional stories, story "Plompf":
[The Pump]
Regarding the discussion which [some of Rebbe Nachman's chassidim] were having about someone who was then in one of the large non-Jewish cities and tarried there a long time because each time he imagined that now he would succeed: and so it was each time, until he was delayed there a long time. And he [the Rebbe] said that that is the way it goes when one comes to such places, that each time it seems to him, "Now I will accomplish, now I will accomplish," etc., etc. And he told this story:
There was one man who did not believe what the world says, that there are leitzim/tricksters from the Sitra Achra/ Other Side that come sometimes to mislead people, as has happened several times; he did not believe this. One night, a leitz came to him and called him to go outside. He went out and the leitz showed him that he had a beautiful horse to sell. He looked and indeed it was a very beautiful horse, so he asked him, "How much do you want?" Answered the leitz, "Four adumim/rubles." He saw that it was easily worth eight rubles, for it was a choice, fine horse. So he bought the horse from him for four rubles and he considered it a great find. The next day, he took the horse out to sell, and people stepped up to purchase and wanted to give him some amount. He said, "Probably, if they are willing to give me so much, it must be worth double!" So he was not satisfied and he took the horse onward, and they wanted to give him twice his desire. He said, "It is probably worth more than double this amount." So he brought the horse onward, until the price of the horse reached into the thousands. However, he was not satisfied with any of them to sell it, for whatever they wanted to give him, he said, "It is probably worth twice as much." Eventually, there was no one who could buy it except the king.
So he brought it to the king, and the king wanted to give him an astounding amount, for the horse was exceedingly pleasing to everyone. However, he was not willing with the king either, for he said, "It is probably worth more." Thus, even the king was unable to buy the horse. So he went from the king with the horse to water it. There was a plomf/pump there from which people take water. The horse jumped into the pump, disappeared and was no more. (That is, it appeared to him as such, for the entire incident of the horse was made up by the leitz). He yelled out loud over this, and people gathered around in response to his screaming and asked him, "Why are you screaming?" He replied that his horse had jumped into the pump. And they beat him [with] injurious blows, for he appeared insane since the opening of the pump is very narrow, and how can a horse jump into it? He saw that they were beating him and that he appeared insane, and he wanted to go from there. As he wanted to leave, the horse began to stick its head out of the pump. So he began to scream again, "Aha, aha (look, look)!" since it appeared to him that his horse was there. The people gathered around and beat him again, since he was insane, as mentioned. Again he decided to leave; and as soon as he wanted to go, the horse again stuck its head out of the pump. He began shouting again as before and the people gathered upon him again and beat him.
Thus the Sitra Achra deceives a man each time with nothingness; complete lies having no substance. And he is incited by it, pursues it, and each time it appears to him that he will profit more and that he will fill his craving more. So he runs after it many times, and suddenly all his desires vanish, get away and go away from him — as has happened many times, that the cravings go away a little, and when the man wants to detach from them, then they come back and stick out their heads and he goes back to chasing them. And so it continues, that as soon as they stick out their heads, he goes back to chasing them. (And he explained the matter no further. Understand this well.)
As an eitzah, advice, though you didn't ask for one, I might offer a piece from Likutei Etzot, section "Prayer":
- Through prayer, one can change nature, subdue, and nullify heretics and Epicureans. (L. Moharan 217)
The best prayer I could recommend in general is "Na Nach Nachma Nachman meUman" because Sabba Y. Odesser said this name and song reverses everything to good.
