
Originally Posted by
Turalyon
I like to think the "spirit" that the Overmind refers to is not related to her "humanity" but to the "darkness" she has never fully embraced (as mentioned at in the manual description of the character). Afterall, she is a willing assassin under the employ of Mengsk and it takes a certain kind of mind to continue being one/to consciously kill people of ones own free will, let alone a very good one which she apparently was.
This can be construed as her having embraced the dark aspect of her true nature. The Zerg "helped" her to do that.
That's the thing - it's not a change/downgrade, but her actually being consistent. Like I said above, the Zerg freed her nature somewhat but she was still controlled by the Zerg. BW then reveals that Kerrigan, freed from all restriction and denial, is really an abhorrent monster at heart - I like to think that that's the "true nature" that the manual refers to. The events that have happened to her eventually lead to the stripping away of all the things that held her back/enslaved (the Confederacy, Mengsk and the Overmind) her true dark nature. I never saw her as a kind, good girl since that perspective is a facile and demeaning portrayal of all female characters in fiction and ignores the fact that anyone willing to continue being an assassin despite paying lip-service to morality is a portrait of a disturbed mind, not a "good/decent" person.