People know as "cutters" are a good example of Biblical demonism. I know of a person whose daughter has this need to cut herself. A number of cults and pagan religions do/did things to draw blood in their rituals as well as ofering human sacrifices.
You won't believe this, Buz, but I've actually heard of a religion whose adherents ritually eat what they say is the body of their deity, and drink what they claim is its blood! Isn't that shocking??!!
Do I take your post to be, at least guardedly, a "yes" answer to the question "is epilepsy caused by demons?" Have my son and I really wasted all that time and money on neurologists and medicine for the last 25 years, when I could have had him exorcised? Are you telling be that Dilantin has anti-demonic properties? Are you completely unaware that self-mutilation is a psychiatric disorder somewhat kin to bulemia/anorexia? Are you really here in the 21st century?
So if demons may well be responsible for mental disorders like my son's form of epilepsy, which responds very well to treatment with drogs like Dilantin or Felbatol, you would agree that these must be Anti-Demon Potions of great efficacy? That the pharmaceutical companies, despite being staffed with card-carrying biologist members of the Intercontinental Evolutionist Conspiracy, are actually putting out antidemonics instead of anticonvulsants?
And why stop with mental ailments? Do measles, yeast infections, and the common cold have a demonic component, or is it just infectious organisms? What about lupus or Crohn's disease, which don't have germs and are perhaps less understood by modern medical science than many forms of epilepsy? Does that mean they're demon-influenced?
A priori, I find the reluctance of many to believe that demons exist most puzzling.
No more puzzling than I find the reluctance of some people to believe that The Invisible Pink Unicorn (PBUHHH!) brought the entire universe, including "memories" of the past, into existence last Tuesday afternoon. That bumfuzzles me completely.