Board Thread:General Discussion/@comment-1535822-20130227140506/@comment-2182964-20130306144648

God actually raises a very good point. Ichigo is, technically speaking, a Human. Even when he fought Byakuya way back when Hollow Ichigo said the spiritual pressure of his own Bankai was crushing his bones (or something to that effect). With that said, even in Soul form, he's got many Human traits other Shinigami simply do not have -- one of which is his ability to use Quincy powers; namely Blut Vene.