Pluto has the last say. When Pluto says “No.”, that’s the end of the conversation, if you can call that one. Pluto has the last say, he holds the power and control over what’s being said. I imagine Mercury is the one who initiates conversations, just like Hermes flew into hell to deliver a message to Hades, that is if Hermes could get out alive. It’s easier for the negative aspect to surface (pun intended) rather than the positive dimensions e.g. deep, empowering thoughts, sex talks to manifest.