Board Thread:General Discussion/@comment-44061-20130307153642/@comment-1387259-20130312040320

Fatdude wrote: Explanation for Ichigo's Shinigami powers. Quincy manipulate Reishi. Rukia put Shinigami Reiatsu in Ichigo, though it was temporary. Maybe Ichigo subconsciously used Quincy techniques on the Reiatsu that Rukia gave him? He normally wouldn't be able to manipulate it, but that could be different in his case since Rukia basically shoved the Reiatsu down his throat. Then maybe his powers adapted to the process of manipulating Reiatsu and Reiryoku, and Ichigo started doing the same to his own Spiritual Power? Hence, making a "Spirit Weapon" out of his own Reiatsu = making a zanpakuto, without an Asauchi base.

That might be one of the most plausible explanations I've heard so far in light of recent information. Guess we won't really know until Kubo decides to stop trolling his readers.