That is a lie.
I don't recall anything about Eastern Orthodoxy and demonism although I think Rasputin was possessed, probably many others.
It's a subject that can make you sick to your stomach. What is so frustrating is that it takes so much power and sometimes many months to get the demons out. From my impression of scripture, Jesus cast them out easily, even the one the disciples couldn't. He did say that kind did not come out except by prayer and fasting.
In the latter case, I believe it was a child or young person who fell on the ground in convulsions which sounds like epilepsy now. Who is to say seizures, at least some, can't be caused by demons?
Heck, the Jews had a concept of Satan. What ignorant people write for the press nowadays.