Styx isn't a garden variety schizo with some vague notion of conjuring demons, he knows enough about demonology that he could spot a poorly informed attempt at mimicking a true believer, unlike some legit schizo on the street who just doesn't have their meds. The amount of academic research that would be needed to craft a fiction sophisticated enough for Tarl to believe that he was dealing with "another legit demonologist" (not a single demonologist is legit, but I am talking in regards to his world view) would almost certainly make the endeavor either fail because he'd spot some detail to know he was dealing with an insincere imitator or be a Pyrrhic victory in terms of investment and reward. Of course, that's just my opinion, I could be wrong.
Added in edit: It would be significantly easier and would require no research to put out a vid being an obvious mockery of a demonologist who cast a spell on Styx the next time that he suffers a misfortune, claiming credit for Styx's misfortune after the fact, much like he did to the D.A./assistant D.A./whatever. An alternative approach would to be to do sufficient research to make a vid purporting to be a sincere believer in demonology to the degree that it was at least convincing enough to hit Poe's law territory (the point where it is not obvious if it is sincere or satire), but whether or not the juice is worth the squeeze is up to the person doing the deed. I don't see it as a good use of time/energy, but others might. The former is has a far better entertainment to investment ratio by my estimation.
