Board Thread:Questions and Answers/@comment-5693502-20141219175924/@comment-5693502-20141219194753

Then why didn't he say Shinigami reiryoku ? He actually says "Shinigami soul" which is why I'm thinking zanpakutō creation is so dark hahaha... because the actual method is super vague to the point of being unknown, I'm only going on the information I've been given.

If zanpakutō really are a conglomeration of Shinigami souls then they'd be similar in structure to Menos (who are a conglomeration of Hollows). That could explain why they're able to do what they do ? I dunno...