I have an overbearing expert sibling like that, and one thing I can tell you is it doesn't change although the theme might change at some point in the future when the ego necessity arises. It's made me minimize my time spent in their presence to the extent possible. The twist for me is that they took my ideas and championed them as their own, so they do what your sib is doing but using my basic views against me like they're the better version of me. For example, if I showed any pride at caring for the environment, they'd join every environmental group, go on environmental missions, then educate me about how to care for the environment instead of polluting like a typical american. Good luck.