The funny thing is, Rainbow Dash has barely used her powers since Nightmare Night way back when. She's also very strongly opinionated on the idea that powers won't solve the problem, that they need to rely on true pony strengths like friendship and compassion instead of strength. So... she has actually learned a very good lesson and is using it to support some bad behavior.

I am honestly not certain how to address her problems given all of that, but OOCly I am downplaying her attitude a lot and keeping her from going down that path as much as possible to avoid the 'not again!' reactions, until I can figure out a way to handle it.