SvtFoE is a deconstruction of the manic pixie dream girl trope. She is really bipolar, with both manic and depressive episodes. It's deep shit. The show seemed superficial at first (intentionally), but it really has the same exact level of forethought, nuance, and professionalism as other noteworthy deconstructions.
SvtFoE will go down in history as a Magic Girl deconstruction, just like Watchmen is remembered for deconstructing cape-stuff, and Neon Genesis Evangelion deconstructing mecha.