NOBODY, including your wife (unless she has forgotten what she was taught) honestly claims that Satan will become god over his own universe. Don’t even go there, because it is not true.
That's not what I said. I said that mormons (and her as well at one time) believe that if they're good enough in this life (through good works)they will later become a god of their own universe. I said nothing about satan becoming god of his own universe.
FYI: That's the classification of ANY cult; that is they believe they will become God or become like God in some way.