I never trusted the Guardian either but at least it felt like a coherent deception and one I could get past.
I don't think the original Dream Visitor was supposed to be much of a deceiver to begin with. It appeared as a direct consequence of you using the powers of the unbidden guest that is lodged in your cranium and as such was implied to be some sort of mental manifestation of your tadpole or the Absolute itself. Everyone knew that it was a shady deal. The pleasant disguise just helps with sweetening it. To me that was definitely more of a temptation than the Guardian telling me to shove additional tadpoles down my throat or... eye socket, I guess.