For instance, a “Priest” with a “Confession” ability or passive that lets all evils communicate with him anonymously at night. The Priest may or may not be able to talk back to them, and of course he would appear anonymous also.
It would be Blue Dragon Social
Before anyone questions whether evils would ever have a motive to communicate anonymously with Blue Dragon, they do it already via deathnotes (usually the evil faction and NK outing each other)