Here's my interpretation of "only one consciousness":
There is only one consciousness, because there is only one real person: I.
I want to enjoy a life as a human, so I create this life role-playing game and enter this game by choosing a particular avatar.
All other people in this life game are only characters that play a role in my life.
Their only purpose is to help me to experience this life game.
It's as simple as that.
