I highly HIGHLY doubt you're actually killing shadows. You don't just kill a side of a person's psyche. One must constantly face and overcome one's shadow but it's not something you just.. terminate. It's an on-going process. --- Bougyo no tame no bougyo nashi. "There is no defense for defense's sake." - Kendo saying. PSN: Spearman-Rho
Shadows are facets of the human psyche, not complete humans. Odds are good killing the shadows makes the person who's psyche it was part of forget something or slightly change their personality.
I always figured that the shadows you were fighting were the shadows of others that never manifested to take the form of the actual person, so i figured that once you kill that shadow, you destroy that person's ability to wield a persona. --- "Check out my sword, it's pretty myth-like."