I cannot express how disappointed I was to go immediately from reading the oneshot and thinking it was pretty good with a nice refreshing setting and setup, to reading the first chapter and being blindsided by them actually just being exorcists dealing with the demons normal people don't know about, and of course the mc is half demon for good measure
I don't know if it was editor meddling, or if the author had no idea how to keep the initial setup going beyond the oneshot, so he dumbed it down of his own accord to have an easier time writing, but fucking hell