Parents are supposed to give the child back to herself with love. If they've got duct tape over their eyes because of narcissism, it doesn't happen.
I dare suggest that the composer would do himself and his music an immediate and eventual service by total, resolute and voluntary withdrawal from this public world to one of private performance and electronic media.
A simple rule in dealing with those who are hard to get along with is to remember that this person is striving to assert his superiority; and you must deal with him from that point of view.

