Re: how to deal with my sempai
Your dojo cho should be making the teaching decisions......if he has got you teaching Tuesday nights then YOU should be teaching. Your sempai sounds like he "knows his role" during class and, if he's not undermining your role as instructor that night, I don't think you have a problem. Again, if he is respectful and defers to you on the mat there is no problem - aside from your feelings......which only you can remedy.
I was at a business seminar the other day and the keynote speaker was talking about how our "small voices" can get in the way of seeing the reality before us.....she said "You are not the voice in your head but your are the one listening". Do you think that maybe you are having more of an internal "battle" deciding what your role should be now that this technically gifted shodan is back at your dojo.....?
Hope that's helpful...,