Just solve it by doing a, "I found traces of a high-ranked demon in this house, and it seems to be possessing someone close to you... wait no it is you." *decapitates head before anyone refutes* "... seems I was wrong, there's still another one somewhere."
Is it bloody? yes. Will it quell the voice of opposition? Yes, especially since I don't know why the lad ain't in charge of the clan and instead a non-blood-related is. Will the populous spread rumors? It's china, of course they will, but would they care? not past a month