How do you kill a pegasus's soul? Put her in charge of the town's weather, then only let her schedule sunny days and gentle evening showers. Not thunderstorms, not blizzards, certainly not hail or tornadoes.
Nothing fun, in other words. Celestia forbid the weather team make some real weather, the kind Rainbow Dash dreams about. The farmers would never stand for that.
Well, screw the farmers. Screw the fashionistas and screw the library princess too if she complains. Rainbow Dash has a dream and she's going to share it with the world, whether the world wants it or not.
A story dedicated to anyone who's ever been passionate about something.