I started writing a brief crash course on Jungian individuation and archetypes, because I thought this bit of meta may need some greater context to not sound half-baked. But I've set it aside because I'm not sure how good a teacher I am, and I don't wish to be too presumptuous, so I will preface this meta with saying that if anyone wants me to explain this stuff a little better, I can give it a shot.
In the meantime, moar Jungian meta for Glee, with one further disclaimer: I do this for fun. This is stuff that comes more from self-study than rigorous academic study, so I invite people who are more skilled and educated in these things to correct, refine, or expand upon my thoughts.
Oh, and FWIW, I'm ignoring gendered stuff between Aminus vs. Anima and who gets which because Jung was stupid about gender. Glee does too many subtle and complex things with gender for that binary distinction to make sense to me anyway.( Blaine needs a new Animus, and he may be getting one. (4x07 spoilers) )
And that's my overthinking for this morning. Getting this stuff out helps me process the emotional fallout from the episode.